ansys problems

Doddakallasandra, Kanakapura Road,

Bangalore-62

DEPARTMENT OF MECHANICAL ENGINEERING

COMPUTER AIDED MODELING AND ANALYSIS LABORATORY - (06MEL67) MANUAL

City Engineering College Bangalore – 560 062

Computer Aided Modeling & Analysis Lab

Dept. of ME

This is to certify that Ms/Mr. ............................................................................................................ has

satisfactorily completed the course of Computer Aided Modeling

and Analysis Lab (06 MEL 67) prescribed by V.T.U. For the VIth

semester B.E. In the year 20 - 20

NAME : ..................................................................

Reg.No. : …………………………………………..

Batch No. : …………………………………………..

Signature of staff in charge Class Marks

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Dept. of ME

06 MEL67 – COMPUTER AIDED MODELING & ANALYSIS LAB

S. No. # Contents Page. No.

1. General Steps For Solving Problems Using Ansys-11.0 4

PART - A

A. (1) Bar With Constant Cross sectional Area. 5

(2) Stepped Bar 7

(3) Bar with tapered cross sectional area. 10

B. Trusses 12

C. (1) Beams – Simply Supported Bema 16

(2) Beam with UDL 18

(3) Beam with UVL 20

PART - B

A.Stress analysis of a rectangular plate with a circular hole

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B.Thermal Analysis – 2D problem with conduction & convection boundary conditions.

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C.Fluid Flow Analysis – potential distribution in the 2-D bodies

29

D. Dynamic Analysis 34

(1) Fixed – fixed beam for natural frequency determination

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(2) Bar subjected to forcing function

(3) Fixed – fixed beam subjected to forcing function.

GENERAL STEPS FOR SOLVING PROBLEMS USING ANSYS – 11.0

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Dept. of ME

1. Ansys Utility Menu File – Clear and start new – Do not read file – pkFile – Change job name - Enter new job name – xxx – okFILE - change title – enter new title – YYY - ok

2. Ansys Main Menu – Preferences Select – STRCTURAL – ok

3. Preprocessor Element Type – select type of element from the table and the required options.Real constants – Give the details such as Thickness, Areas, Moment of Inertia etc. required depending on the nature of the problem.Material properties – select units – choose one of the following types of unit.

USER – User defined system (default)SI - International system (SI or MKS; m, kg, ˚K).CGS - CGS system (cm, g, s, ˚C).MPA - MPA system (mm, Mg, s, ˚C).BFT - British system using feet (ft, slug, s, ˚F).BIN - British system using inches (in, lbf*s2/in, s. ˚F).

Material Properties – Give the details such as Young’s modulus. Poisson’s ratio etc. required depending on the nature of the problem.

4. Modeling Create the required geometry such as nodes, elements, area, volume by using the appropriate options.

5. Generate Elements / nodes using Mesh tool if necessary (in 2-D and 3-D problems).

6. Apply the Boundry conditions/loads Such as DOF constraints, Force. Momentum, Pressure etc.

7. Solution – Solve the problem.

8. General Post Processor – Plot / List the required results.

9. Plot ctrls – animate – deformed shape – def + undeformed – ok

10. To save the solution / geometry etc: Ansys tool bar – Save – DB – File – save as – zzz.db – ok

11. To open the solution / geometry etc: Ansys tool bar – Resume – DB – File – Resume from – zzz.db – okPlot – volume / area / elements / nodes to see the geometry.

PART – A

A – Bars of constant cross section area

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Dept. of ME

Problem No. – 1: Consider the bar as shown in figure below. Determine

(1) The nodal displacement (2) Reaction forces.

Given: L = 300 mm, D = 50 mmE = 2.1 * 105 N/mm2, F2 = 1500 N

By manual calculations we obtain;(a) The displacements as; {d}T = [0 0.0010909] mm(b) The stresses in each elements will be;

σ = 0.76363 N/mm2

(c) The reaction forces are;R1 = -1499.988 -1500 N

Procedural steps for solving:

1. Ansys Utility Menu File – Clear and start new – Do not read file – okFile – Change job name – Enter new job name – xxx – okFile – Change title – Enter new title – yyy – pk

2. Ansys Main Menu – Preferences Select – STRUCTURAL – OK

3. Preprocessor Element type – Add/Edit/Delet – Add – Beam 2D elastic 3 – ok – closeReal constants – Add – ok – real constant set no.1 for beam – real constant set no. 1 for beam – cross sectional area – enter 1963.495 mm2; moment of inertia about z – 0.3068*106 mm4 – ok – close.

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Dept. of ME

Material properties – Material Model - Material Model Number 1 – Structural – double click – linear – double click – Elastic – Isotropic – double click – 2E5 – (If required enter PXY) – ok - close

4. Preprocessor Modeling – Create – Nodes – in active CS – x.y.z location in CS (default 0.0.0) – apply – x.y.z location in CS – 300.0.0 – okCreate – elements – elem attributes – Element type no – 1BEAM 3 – Material no – 1 – Real const set no – 1 – ok – Auto numbered – thru nodes – pick 1 & 2 – ok (elements are created through nodes)

5. Preprocessor Loads – Define Loads -Apply –Structural displacement-on nodes –pick node 1-apply –DOF to be constrained –ALL DOF –ok Loads –define loads Apply - Force \ moment - on nodes - pick node3 apply direction of Force \ moment – FX - Force \ moment value -1000 (value) – ok

6. Ansys main Menu – solutionSolve – Solve current LS - ok (displayed) Solution is done is close

7. Ansys main menu – General post processor List resultsNoda! Solution favorites –nodal solution –X-component of displacement –ok (for displacement in X direction with the node number)

Stepped Bar

Problem No. – 2: Consider the bar as shown in figure below. Determine (1) The nodal displacement (2) Reaction forces.

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Dept. of ME

Given: E2 = 0.7*105 N/mm2, A2 = 600 mm2

E1 = 2.0 * 105 N/mm2, A1 = 900 mm2




3. Preprocessor Element type – Add/Edit/Delet – Add – Beam 2D elastic 3 – ok – closeReal constants – Add – ok – real constant set no.1 for beam – cross sectional area – enter ***; moment of inertia about z – **** – apply.Real constants – Add – ok – real constant set no. 1 for beam – cross sectional area – enter *** (value); moment of inertia about z – ****Material properties – Material Model - Material Model Number 1 – Structural – double click – linear – double click – Elastic – Isotropic – double click – 2E5 – (If required enter PXY) – ok Material Model Number 2 – Structural – double click – linear – double click – Elastic – Isotropic – double click – 0.7E5 – (If required enter PXY) – ok – close.

4. Preprocessor Modeling – Create – Nodes – in active CS – x.y.z location in CS (default 0.0.0) – apply (node 4 is created) – x.y.z location in CS – 600.0.0 – apply (node 5 is created) – x, y, z location in CS – 1100.0.0 – ok (node 6 is created)

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Dept. of ME

Create – elements – elem attributes – Element type no – 1BEAM 3 – Material no – 1 – Real const set no – 1 – ok – Auto numbered – thru nodes – pick 4 & 5 – ok (element 1 is created) elements – elem attributes – Element type no – 1BEAM 3 – Material no – 2 – Real const set no – 2 – ok – Auto numbered – thru nodes – pick 5 & 6 – ok (element 2 is created).

5. Preprocessor Loads –Define Loads -Apply –Structural displacement-on nodes –pick node 4-apply –DOF to be constrained –ALL DOF –ok Loads –define loads Apply - Force \ moment - on nodes - pick node 6 apply direction of Force \ moment – FX - Force \ moment value -500 (value) – ok


7. Ansys main menu – General post processor List resultsNodal Solution favorites –nodal solution –X-component of displacement –ok (for displacement in X direction with the node number)

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Dept. of ME

Bar of tapered cross section area

Problem No. – 3: For the following bar, find the displacements. The cross sectional area

decreases linearly from 1000 mm2 to 500 mm2. Use two elements. Take E = 2 x 105 Mpa. ν = 0.3.

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Dept. of ME

Given: L = 300 mm, D = 50 mmE = 2.1 * 105 N/mm2, F2 = 1500 N




3. Preprocessor Element type – Add/Edit/Delet – Add – Beam 2D tapered 54 – ok – closeReal constants – Add – ok – real constant set no.1 for beam – real constant at beam end I – node I - cross sectional area – enter 1000 - moment of inertia about z – 159.16 x 103 – real constant at beam end 2 – node J – cross sectional area – enter 750 – moment of inertia about z – 89.53 x 103 – apply.Add – ok – real constant set no 2 for beam – real constant at beam end I – node I – cross sectional area – enter 750 – moment of inertia about z – 89.53 x 103 – real constant at beam end 2 – node J – cross sectional area – enter 500 – moment of inertia about z – 39.79 x 103 – ok – close.Material properties – Material Model - Material Model Number 1 – Structural – double click – linear – double click – Elastic – Isotropic – double click – 2E5 – (If required enter PXY) – ok - close

4. Preprocessor Modeling – Create – Nodes – in active CS – x.y.z location in CS (default 0.0.0) – apply – x.y.z location in CS – 375.0.0 – apply – 750, 0, 0 - okCreate – elements – elem attributes – Element type no – 1BEAM 54 – Material no – 1 – Real const set no – 1 – ok – Auto numbered – thru nodes – pick 1 & 2 – apply – ele attributes – element type no – 1 BEAM 54 – Material no – 1 – real const set no – 2 – ok – auto numbered – thru nodes – pick 2 & 3 - ok (elements are created through nodes)

5. Preprocessor

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Dept. of ME

Loads – Define Loads -Apply –Structural displacement-on nodes –pick node 1-apply –DOF to be constrained –ALL DOF –ok Loads –define loads Apply - Force \ moment - on nodes - pick node3 apply direction of Force \ moment – FX - Force \ moment value -1000 (value) – ok


7. Ansys main menu – General post processor List resultsNoda! Solution favorites –nodal solution –X-component of displacement –ok (for displacement in X direction with the node number)

B - TRUSSES

Problem Number 1:Consider the four bar truss shown in figure. For the given data, find

(i) Stress in each element(ii) Reaction forces(iii) Nodal displacement.

E = 29.5 x 106 units; A = 1 units for all elements.

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Dept. of ME


1. Ansys Utility Menu FILE – Clear and start new - do not read file – ok FILE - change job name – enter new job name – XXX - okFILE - change title – enter new title – YYY - ok

2. Ansys Main Menu – Preferences Select – STRCTURAL – ok

3. To define element; Preprocessor: Element type – Add/Edit/Delete – Add – Link – 2D spar 1 – ok – close.

4. To define element Real constant: Preprocessor: Real constants – Add – ok – real constant set no – 1 – c/s area – 1 – ok.

5. To define element Material properties: Preprocessor: Material properties – Material Model – Material Model Number 1 – Structural – double click – Linear – double click – Elastic – Isotropic – double click – 29.5E6 – (If required enter PXY = 0.3) – ok – enter – close.

6. To creat Nodes: Preprocessor: Modeling – creat – Nodes – in active CS – now enter the co-ordinates of the nodes to be created – apply [create first node by entering 0,0,0 (x1, y1, z1) second node by 40,0,0 (x2, y2, z2) third node by 40,30,0 (x3, y3, z3) and fourth node by 0,30,0 (x4, y4, z4) respectively along x, y, z direction location].

7. To create Elements:

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Dept. of ME

Preprocessor: Modeling – create – elements – element attributes – Element type no – 1; Link 1 – Material no – 1 – Real constant set no – 1 – ok.Click – Auto numbered – thru nodes – pick node no 1 & node no 2 – apply – pick node no 2 & node no 3 – apply – pick node no 3 & node no 1 – apply – pick node no 3 & node no 4 – ok (elements are created through nodes).

8. To apply boundary conditions: Preprocessor: Loads – Define loads – Apply – Structural Displacement – on nodes – pick nodes 1 & 4 – apply – click All DOF – ok.Loads – Define loads – Apply – Structural Displacement – on nodes – pick node 2 – apply – DOF to be constrained UY – ok.

9. To apply Loads: Preprocessor: Loads – Define Loads – Apply – Force/Moment – on nodes – pick node 2 – apply – direction of Force/Moment – FX – Force/Moment value - +20,000 (positive value) – apply.Preprocessor: Loads – Define Loads – Apply – Force/Moment – on nodes – pick node 3 – apply – direction of Force/Moment – FY – Force/Moment value - -25,000 (negative value) – ok.

10. To solve the problem: Ansys Main Menu – Solution – solve current LS – ok (if every thing is ok – solution is done is displayed) – close.

11. To interept the Result: General Post Processor

1. To plot the element stresses:Ansys Main Menu – General Post Processor – Element table – define table – add – results data item – By sequence num – select LS – enter – LS1 – ok (to see the element stress)

General Post Processor – Element table – plot element table – select LS1 – click ok.

General Post Processor – plot results – contour plots – Line element results – element table item at node 1 – LS1 – element table item at node J – LS1 – ok (stress diagram will be displayed).

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Dept. of ME

2. To plot Deformed Shape:General Post Processor – plot results – deformed shape – pick def + undeformed – ok (deformed + undeformed shape of truss will be displayed).

3. To plot deformed shape:Main menu – Plot ctrls – animate – deformed shape – def + undeformed – ok.

4. To List the Nodal Solutions.General Post Processor list results – Nodal solution – DOF solution – x component – ok (Nodal displacements will be displayed).

General Post Processor – list results – Reaction solution – items to be listed – all items – ok (All reaction forces will be displayed with the node numbers).

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Dept. of ME

C – Beams

Problem no – 1: Simply Supported Beam

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Dept. of ME

Simply supported beam subjected to concentrated loads. Compute the shear force and bending moment diagrams for the beam shown and find the reactions at the supports.


1. Ansys Utility Menu File – Clear and start new – Do not read file – okFile – Change job name – Enter new job name – xxx – okFile – Change title – Enter new title – yyy – ok


3. Preprocessor Element type – Add/Edit/Delet – Add – Beam 2D elastic 3 – ok – closeReal constants – Add – ok – real constant set no.1– cross sectional area – enter 200*300 mm2; area moment of inertia –200*300**3/12mm4 – total beam height – 300 - ok – close.Material properties – Material Model - Material Model Number 1 – Structural – double click – linear – double click – Elastic – Isotropic – double click – 2E5 – (If required enter PXY) – ok – close

4. Preprocessor Modeling – Create – Nodes – in active CS – apply (first node is created) – x, y, z location in CS – 1500 (x value w.r.t first node) – apply (second node is created) – 3000 (x value w.r.t first node) – apply (third node is created) – 4000 (x value w.r.t first node) – ok Create – elements – Auto numbered – thru nodes – pick 1 & 2 – apply –pick 2 & 3 – apply - pick 3 & 4 - ok (elements are created through nodes).

5. Preprocessor Loads – define loads – apply – structural – Displacement – on nodes – pick nodes 1 & 4 – apply – DOF to be constrained – UY – ok.Loads – define loads – apply – Force – on beams – pick 2 & 3 – apply – direction of force/moment – FY – force value - -20000 & -40000 - ok

6. Ansys Main Menu – Solution Solve – solve current LS – ok (if everything is ok – solution is done is displayed) – close

7. Ansys Main Menu – General Post Processor Element table – define table – add – results data item – By sequence num – smisc – smisc 2 – apply – By sequence num – smisc – smisc 8 – apply

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Dept. of ME

– By sequence num – smisc – smisc 6 – apply – By sequence num – smisc – smisc 12 – apply.

8. General Post Processor Plot results – Contour plots – line elem results – element table item at node I – smisc 2 – element table item at node J – smisc 8 – ok (shear force diagram will be displayed) Line elem results – element table item at node I – smisc 6 – element table item at node J – smisc 12 – ok (bending moment diagram will be displayed)

Note: For shear force diagram use the combination smisc 2 & smisc 8.And for Bending Moment diagram use the combination smisc 6 & smisc 12.

List resultsNoda! Solution favorites –nodal solution –X-component of displacement –ok (for displacement in X direction with the node number)

Problem no. – 2: Beam with UDLSimply supported beam with uniformly distributed load. (All dimensions in

mm.)

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Dept. of ME





4. Preprocessor Modeling – Create – Nodes – in active CS – apply (first node is created) – x, y, z location in CS – 4000 (x value w.r.t first node) – apply (second node is created) – 6000 (x value w.r.t first node) – ok (third node is created)Create – nodes – fill between Nodes – pick 1 & 2 – apply – no. of nodes to fill – 7 – starting node no. – 4 – ok.Create – elements – Auto numbered – thru nodes – pick 1 & 4 – apply – pick 4 & 5 - apply – pick 5 & 6 – apply – pick 6 & 7 apply – pick 7 & 8 – apply – pick 8 & 9 – apply – pick 9 & 10 – apply – pick 10 & 2 – apply – pick 2 & 3 – ok (elements are created through nodes).Note: Elements between nodes 1 & 2 also can be created with copy option.

5. Preprocessor Loads – define loads – apply – structural – Displacement – on nodes – pick nodes 1 & 3 – apply – DOF to be constrained – UY – ok.

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Dept. of ME

Loads – define loads – apply – Pressure – on beams – pick all elements between nodes 1 & 2 – apply – pressure value at node I – 12 (value) – pressure value at node J – 12 (value) – ok


7. Ansys Main Menu – General Post Processor Element table – define table – add – results data item – By sequence num – smisc – smisc 2 – apply – By sequence num – smisc – smisc 8 – apply – By sequence num – smisc – smisc 6 – apply – By sequence num – smisc – smisc 12 – apply.




Problem no. – 3: Beam with UVLSimply supported beam with uniformly varyuing load. (All dimensions in

mm.)

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Dept. of ME





4. Preprocessor Modeling – Create – Nodes – in active CS – apply (first node is created) – x, y, z location in CS – 3000 (x value w.r.t first node) – apply (second node is created) – 4500 (x value w.r.t first node) – ok (third node is created) – 6000 (x value w.r.t first node) - okCreate – elements – Auto numbered – thru nodes – pick 1 & 2 – apply – pick 2 & 3 – apply – pick 3 & 4 - ok (elements are created through nodes).

5. Preprocessor Loads – define loads – apply – structural – Displacement – on nodes – pick nodes 1 & 4 – apply – DOF to be constrained – UY – ok.Loads – define loads – apply – Pressure – on beams – pick elements between nodes 1 & 2 – apply – pressure value at node I – 0 (value) – pressure value at node J – 40(value) – ok – loads – apply – structural – force – on nodes – pick node 3 – apply – FY - -80000 - ok


7. Ansys Main Menu – General Post Processor

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Dept. of ME

Element table – define table – add – results data item – By sequence num – smisc – smisc 2 – apply – By sequence num – smisc – smisc 8 – apply – By sequence num – smisc – smisc 6 – apply – By sequence num – smisc – smisc 12 – apply.




Reaction force:

PART – B

A – Stress analysis of a rectangular plate with a circular hole.

In the plate with hole under plane stress find deformed shape of the hole and determine the maximum stress distribution along A-B (you may use

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Dept. of ME

t=10mm) E= KN\mm t=10mm poisson ratio =0.3. Diameter of circle =40mm. Analysis assumption plane stress with thickness is used.

FOR 2-D and 3-D problems after the geometry has been created meshing is to be done (elements \ nodes are created) Procedural steps for solving:


2. Ansys Main Menu - Preferences Select – STRCTURAL – ok

3. Preprocessor Element Type – Add/Edit/Delete – Add – Solid – Quad 4 node / 8node – 42/82 – ok – option – element behavior k3 – plane stress with thickness – ok – close. Real constants – Add – THK – 10 – okMaterial properties – Material Model – Material Model Number 1 – Structural – double click – Linear – double click – Elastic – Isotropic – double click – 2E5 – (If required enter PXY = 0.3) – ok – enter – close

4. Preprocessor Modeling – Create – Areas – rectangle – by dimensions – X1, Y1, X2, Y2 = 0, 0, 200,100 – ok – create – areas – circle – solid circle – rad – 20 – ok.Operate – subtract – areas – pick area which is not to be deleted – apply – pick area to be deleted (circle) - okMesh tool – smart size on (select any value, say 4) – mesh – pick area to be meshed – apply – if refining is required at some place – refine – select box/circle – drag on the area – level of refinement – 2 – ok.

5. Preprocessor Loads – Define loads – Apply – structural displacement – on nodes – box – drag box left side of area (to pick all nodes) – apply – DOF to be constrained – all DOF – ok.

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Dept. of ME

Loads – Define loads – apply – pressure – on nodes – box – drag right side of area (to pick all nodes) – apply – pressure value – (-2000) (value) – ok – close.


7. Ansys Main Menu – General Post Processor Plot results – Counter Plots – Element solution – stress – Von mises stress – ok (stress distribution diagram will be displayed)

Plot result – deformed shape – pick def + undeformed – ok (deformed + undeformed shape will be displayed)

Plot ctrls – animate – deformed shape – def + undeformed – ok

Query results – nodal solution – stress – Von mises stress – ok – select any location on area – value displayed.

List results – nodal solution – DOF solution – All DOF’s – ok – values displayed – nodal solution – stress – Von mises stress – ok – values displayed.

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Dept. of ME

B – Thermal Analysis

2 – D Problem with conduction and convection boundary conditions

Problem 1: For the composite wall idealized by the 1 – D model shown in figure below, determine the interface temperatures. For element 1, let K1 = 5 W/m˚C, for element 2, K2 = 10 W/m˚C, and for element 3, K3 = 15 W/m˚C. The left end has a constant temperature of 200˚C and the right end has a constant temperature of 600˚C.

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Dept. of ME

Solution:Finite Element Model:



2. Ansys Main Menu - Preferences Select – THERMAL – ok

3. Preprocessor Element Type – Add/Edit/Delete – Add – Link – 2-D conduction – 32 – ok – close Real constants – Add/Edit/Delete - Add – type 1 – link 32 – real constant set no 1 – cross sectional area – enter – 0.1 – ok - closeMaterial properties – Material Models – Material Model Number 1 – Thermal – conductivity – isotropic – conductivity for material – thermal conductivity (Kxx) – 5 – ok – material – new model – define material 1D – 2 – ok – thermal – conductivity – isotropic – conductivity for material – thermal conductivity (Kxx) – 10 – ok – material – new model – define material 1D – 3 – ok – thermal – conductivity – isotropic – conductivity for material – thermal conductivity (Kxx) – 15 – ok – close.

4. Preprocessor Modeling – Create – Nodes – in active CS – x, y, z location in CS – 0, 0, 0 (x,y,z value w.r.t first node) – apply (first node is created) – 0.1, 0,0 – apply (second node is created) – 0.2,0,0 – apply (third node is created) – 0.3,0,0 – apply (fourth node is created) - ok

Create – elements – element attributes – select material number – 1 – real constant set number – 1 – Auto numbered – thru nodes – pick nodes 1

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Dept. of ME

& 2 (element 1 is created) – ok – element attributes – select material number – 2 – real constant set number – 1 – Auto numbered – thru nodes – pick 2 & 3 (element 2 is created) – ok – element attributes – select material number – 3 – real constant set number – 1 – Auto numbered – thru nodes – pick 3 & 4 (element 3 is created) – ok

5. Loads Define Loads – Apply – thermal – select temperature – on nodes – pick node 1 – apply – select – TEMP – value - 200 – apply – pick node 4 - apply – select – TEMP – value – 600 – ok

6. Ansys Main Menu Solution – Solve current LS – ok (if everything is ok – solution is done is displayed) – close.

7. Ansys Main Menu General Post Processor – Plot results – Contour plots – Nodal solution – DOF solution – temp – ok (Temperature distribution plot)

List Result – nodal solution – DOF solution - temp – ok (Temperature at all nodes will be created)

Plotctrls – Animate – Deformed results – DOF solution – Temperature – ok (for animation).

Problem 2:For the body shown in fig determine the temperature distribution the body is insulated along top and bottom edges

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Dept. of ME

Solution:



2. Ansys Main Menu - Preferences Select – THERMAL – ok

3. Preprocessor Element Type – Add/Edit/Delete – Add – solid quad 4 node 55 ok – close Real constants – no real constants Material properties – Material Models – Material Model Number 1 – Thermal – conductivity – isotropic – conductivity for material – thermal conductivity (Kxx) – 1.7307– ok – close

4. Preprocessor Modeling – Create – Nodes – in active CS – x, y, z location in CS – 0, 0, 0 (x,y,z value w.r.t first node) – apply (first node is created) –4 , 0,0 – apply (second node is created) –8,0,0 – apply (third node is created) –0,2.5,0 – apply (fourth node is created) –2,2.5,0 – apply (fifth node is created) 8,2.5,0 – apply (sixth node is created)- 8,5,0 – apply (seventh node is created) 4,5,0 – apply (eighth node is created)0,5,0 – apply (ninth node is created) - ok

Create – elements – element attributes – select material number – 1 –Auto numbered – thru nodes – pick nodes 1 ,2,5,4 (element 1 is created) – ok – pick 2 ,3,6,5 (element 2 is created) – ok – pick 4,5,8,9 (element 3 is created) –pick 5, 6, 7, 8 (element 4 is created) ok

5. Preprocessor:

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Dept. of ME

Loads – define loads – apply- thermal – temperature- on nodes- pick inner surface – apply- temp- 40- ok

Loads – define loads – apply- thermal – temperature- on nodes- pick -outer surface – apply- temp- 20- ok

Loads-define loads – apply – thermal – heat flux – on nodes- pick – top surface – apply – heat flux -0 (value) – apply – heat flux- on nodes- pick bottom surface – apply – heat flux – 0-ok

6. Ansys main menu Solution – solve- current LS – ok (if everything is ok – solution is done is displayed) – close.

6. Ansys main menu General postprocessor – plot result – contour plots – nodual solution - DOF solutions- temp – ok.

List result – nodual solution- temp-ok

Plot controls – animate - deformed result – DOF solution - temp – ok.

C – Fluid Flow Analysis

Potential Distribution in the 2-D Bodies

Problem 1: (Flow over the cylinder)Atmospheric air at 20˚C flows with a velocity of 5 mm/s over a long

horizontal cylinder of diameter 25 cm. Compute and plot the velocity distribution of air over the cylinder. The cylinder is 0.25 m in diameter.

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Dept. of ME

Considering symmetry about horizontal, only the upper half of the cylinder is computed. The results are assumed to be the same below the x axis (axis of symmetry). The arbitrary flow area considered is 2 m by 0.5 m. The velocity of the air at infinite distance from the plate is 5 mm/s (0.005m/s) (Laminar flow).



2. Ansys Main Menu - Preferences Select – Flotran CFD – H method – ok

3. Preprocessor Element Type – Add/Edit/Delete – Add – Element type – Flotran CFD – 2D Flotran 141 – ok

4. Preprocessor Modeling – Create – Areas – Rectangle – By 2 corners – x = 0, y = 0, width = 2, height = 0.5 – okCreate – Areas – circle – Solid circle – x = -5, y = 0, radius = 0.25 – okOperate – Booleans – Subtract – Areas – pick the rectangle – ok and then pick the circle by above method – ok

5. Preprocessor Meshing – Size controls – Lines – All lines – Element edge length – 0.02 – okMesh – Areas – Free – Pick the Element – ok

6. Preprocessor Flotran set up – Fluid properties – select density – Air-SI, velocity – Air-SI, Conductivity – constant, Specific heat – constant – ok – in CFD flow properties enter constant value for conductivity and specific heat = -1 – ok.

7. From the menu bar – select plot – lines – ok

8. Preprocessor

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Dept. of ME

Loads – define loads – apply – fluid/CFD – velocity – on lines – pick the lines (pick left and top lines) – ok – apply VX load – constant value, VX load value – 0.005, VY load value – 0, VZ load – constant value, VZ load value – 0 – okLoads – Define loads – apply – Fluid/CFD – velocity - on lines – pick the bottom line with out picking curve – ok – VX load value – 0, VY load value – 0 – ok.Loads – Define loads – apply – Fluid/CFD – velocity – on the lines – pick the curve – ok, put VX load value – 0, VY load value – 0 – ok.Loads – define loads – apply – fluid/CFD – pressure DOF – on the lines – pick the right line – ok, apply pressure on the line – constant value, pressure value – 0 – ok.

9. Preprocessor Solution – execution control – enter global iteration – 1000, VX velocity component – 0.01, VY component – 0.01, VZ component – 0.01, pressure – 1e-008, temperature – 1e-008, turbulent kinetic energy – 0.01, turbulent dissipation – 0.01, output summary frequency – 10 – okSolution – Run Flotran (Flotran solution with a graph will appear) – solution is done – close.

10. General Post Processor Read result – Last setPlot result – Contour plot – nodal solution – DOF solution – select fluid velocity, deformed shape only – ok (study the nodal solution of graph).Plot results – vector plot – predefined – select DOF solution – velocity V – vector mode – element centroid – vector scaling – magnitude based – ok (study the predefined vector plot)Plot result – Define trace point – pick the different elements inside the boundary – ok, from the menu bar select plotctrls – animate – particle flow – number of frames to create – 10, time delay – 0.1, spacing and size factor – 1, particle length factor – 0.2, maximum number of loops – 25, select DOF solution - velocity VX – ok, study the animation graph and close.

Problem 2: (Flow over a flat plate)Atmospheric air flows over a flat plate with a velocity of 0.5 m/s. Compute

and plot the velocity boundary layer for flow of air over the plate and find velocity distribution at a distance of 0.5 m from the leading edge. Assume the plate is 1m long. The arbitrary flow area considered is 1m by 0.25 m. The free stream velocity of the air is 0.5 m/s. Atmospheric pressure is assumed on all faces except the face where velocity is input into the system.

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2. Ansys Main Menu - Preferences Select – Flotran CFD – H method – ok

3. Preprocessor Element Type – Add/Edit/Delete – Add – Element type – Flotran CFD – 2D Flotran 141 – ok

4. Preprocessor Modeling – Create – Areas – Rectangle – By 2 corners – x = 0, y = 0, width = 1, height = -0.25 – ok

5. Preprocessor Meshing – size control – manual size – lines – picked lines – pick the bottom and top line – ok – enter number of element divisions – 50 – apply – now select the front line and back line – ok – enter the number of element divisions – 100 – spacing ratio – 10 – okMeshing – size control – manual size – lines - flip bias – pick all lines – ok.Meshing – mesh tool – mesh – areas - free – select the area – ok (observe the mesh)

6. Preprocessor Flotran setup – fluid properties – enter density – AIR-SI – ok – (in CFD flow properties dialog box), viscosity property constant value – 0.5, conductivity constant value – (-1) and specific heat constant value – (-1) – ok

7. Preprocessor Loads – define loads – apply – fluid/CFD – velocity – on lines – pick the front line and the top line – apply – enter VX load value – 0.5, VY value – 0, VZ value – 0 – apply to end points – click yes – okLoads - define loads – apply – fluid/CFD – velocity – on lines – pick the bottom lines – ok – enter VX load value – 0, VY value – 0, VZ value – 0 – apply to end points – click yes – ok

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Dept. of ME

Loads - define loads – apply – fluid/CFD – pressure DOF – on lines – select the right corner line – ok – enter pressure value – 0, apply to end points – click yes – ok.

8. From Menu bar select plot – lines – all lines – ok

9. Solution Flotran setup – execution control – enter global iterations – 400 – VX, VY, VZ velocity component – 0.01 – pressure and temperature – 1e-008 – turbulent kinetic energy and turbulent descipation – 0.01 – output summary frequency – 10 – okRun Flotran – solution is done – close (study the graph)

10. General Post processor Read result – last set – okPlot result – contour plot – nodal solution – select dof solution and fluid velocity, deformed shape only – ok (study the graph)Plot result – vector plot – predefined – select dof solution, velocity v – enter scale factor multiplier – 0.4 – ok (study the graph)Select entities – nodes – by location – x co-ordinates – min max – 0.5 – okFrom the menu bar – select plot – nodes – pick the points inside the boundary - study the graphFrom the menu bar – select plot controls – animate – particle flow.Path operations – define path – by nodes – pick the two nodes – ok – enter – the path name – x 50, number of date sets – 30 and number of divisions – 20 – okMap on to path – select velocity from the user label – dof solution – velocity VX – okPath operation - plot path item – on graph (study the graph)List results – path item – select velocity – ok – observe the path variable summary.

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Dept. of ME

Dynamic Analysis

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Dept. of ME

Modal Analysis of a Fixed –Fixed Beam

Aim: To determine the natural frequencies (Eigen values) and corresponding mode shapes (Eigenvectors) of a given fixed beam

IntroductionThis tutorial is created using ANSYS 9.0.The purpose of this tutorial is to outline the steps required to the do the simple model of fixed –fixed beam-shown below five lowest natural frequencies and their corresponding mode shapes of the beam are obtained

Modules of elasticity E= Poisson s ratio =µ=0.3Density, α=7830kg/m3

Preprocessing :

Define Analysis Type:Solution -analysis type -new analysis-model

Creation of Fixed Beam used in Modal Analysis Creation of any beam can be obtained through GUI (Graphic User Interface) of ANSYSS using the following steps

1. Open Preprocessor Menu

2. Give example a Title Utility menu -file change title Enter fixed –fixed beam for the title

3. Give example a job name Utility menu -file change job nameEnter dynamic for the job name

4. Define Element Types Preprocessor -Element type -Add/ Edit/ Delete For this problem the BEAM 3(Beam2Delastic) element is used this element has 3d of (i.e. translation along X and Y axes and rotation about Z axis) with only 3d of the BEAM3element can be used in analysis.

5. Define Real Constants

Preprocessor- Real Constants-Add.

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Dept. of ME

In the Real Constants for BEAM3window enter the flowing geometric properties.

i. Cross sectional area AERA :0.001x0.001=0.0001M2

ii. Area moment of Inertia

iii. Total beam height HEGHT: 0. 01m

6. Define Element Material Properties Preprocessor-material props -Material Models -Structural -Linear - Elastic - isotropic In the window that appears enter the following material properties of the beam (here it is steel)

i. Young s modules EX:2.068e11ii. Passions Ratio PRXY :0.3

To enter density of the material double click on linear followed by density in the define material model behavior window and enter a density of 7830

7. Create Key Points Preprocessor-modeling - create - key points - in active csDefine 2 key points (the beam vertices) for this structure along with the coordinates as given in the flowing table

Key point Coordinates(x,y,z)1 (0,0,0)2 1,0,0)

8. Define Lines Preprocessor-modeling - create - Lines-straight line

Create a line between key point 1and key points 2

9. Define Mesh Size Preprocessor-meshing - size cntrls - manual size - lines - all lines

10. Mesh the Frame Preprocessor-meshing -mesh - lines - click pick all in the small window appears

Solution

Solution –analysis type-analysis options-change subspace –enter 5 no of modes to extract-expand modes shapes and enter 5 no of modes to expand – ok

Apply constrain Solution-define loads- apply- structural -displacement-on key points-fix all the key points of no 1 and 2

Solution-solve –current ls-solve

Post Processing

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Dept. of ME

General post proc-result summery

To view mode shapesGeneral postproc-read results-first setGeneral postproc-plot results-deformed shapesGeneral postproc-read results-next setGeneral postproc-plot results-deformed shapesAnimate mode shapesUtility menu-plotctrls-animate-mode shapes

Fixed – Fixed Beam For Natural Frequency Determination

The simple harmonic analysis of a fixed-fixed beam subjected to cyclic load as shown below.

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Dept. of ME

E = 2.068E+11 N/mm2 ;Poisson’s ratio = 0.3; Density = 7830 kg/m3;Magnitude = 100 N; Frequency range = 0 – 300 Hz;

Preprocessing:

1. Solution – analysis type – new analysis – harmonic

2. Preprocessor - Element type - Add/ Edit/ DeleteFor this problem the BEAM 3(Beam2Delastic) element is used this element has 3d of (i.e. translation along X and Y axes and rotation about Z axis) with only 3dof the BEAM3element can be used in analysis.

3 Define Real Constants

Preprocessor - Real Constants-Add.In the Real Constants for BEAM3window enter the flowing geometric properties.

i. Cross sectional area AERA :0.001x0.001=0.0001M2

ii. Area moment of Inertiaiii. Total beam height HEGHT: 0. 01m

4. Define Element Material Properties Preprocessor-material props -Material Models -Structural -Linear - Elastic - isotropic In the window that appears enter the following material properties of the beam (here it is steel)

i. Young s modules EX:2.068e11ii. Passions Ratio PRXY :0.3

To enter density of the material double click on linear followed by density in the define material model behavior window and enter a density of 7830

5. Create Key Points Preprocessor - modeling - create - key points - in active csDefine 2 key points (the beam vertices) for this structure along with the coordinates as given in the flowing table

Key point Coordinates(x,y,z)1 (0,0,0)2 1,0,0)

6. Define Lines Preprocessor - modeling - create – Lines - straight line

Create a line between key point 1and key points 2

7. Define Mesh Size Preprocessor-meshing -size cntrls - manual size -lines -all lines

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Dept. of ME

8. Mesh the Frame Preprocessor-meshing -mesh - lines -click pick all in the small window appears

Solution1. Solution – analysis type – analysis option – select full solution method the

real + imaginary DOF – ok2. Solution – define loads – apply – structural – displacement – on nodes –

pick key point no – 1 and 2 – all DOF – ok3. Solution - define loads –apply – structural – force moment – pick centre

node (x = 0.5) – direction FY – value real part of force/moment – 100 – ok4. set of frequency range

solution – load step Opts – time / frequency – freq and sub steps – harmonic frequency range – 0-300 – number of sub steps – 300 – stepped - ok

5. solution – solve – current LS

Viewing the result Time hist processing – variable viewer (the following window will pop up)

Select from the window – nodal solution – DOF solution – Y component – okGraphically select the node 2 when prompted and click ok – the time history variable window will appear.Time history variable – list – following window will be appear

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Dept. of ME

Plot UY Vs frequency Time variable window – plot – than graph will be plottedSelect utility menu - plot control – style – graph – modify axis – change the Y axis scale to logarithmic.Select utility menu – plot – re-plot

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Dept. of ME

VIVA QUESTIONS

1. What is stress, strain, deformation?2. What is yield point, ultimate point?3. What is poisons ratio?4. What is an elastic constant?5. What is young’s modulus, rigidity modulus, bulk modulus?

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Dept. of ME

6. What is lateral and longitudinal strain?7. What is shear force, bending moment?8. What is slope and deflection?9. Write polar modulus rigidity?10. What is section modulus?11. Write moment of inertia for circular, rectangular, hollow rectangular and

hollow circular section?12. What is normal stress, shear stress?13. What is compound stress?14. What is principal stress?15. What is principal plane?16. Explain theories of failure?17. What is maximum principal stress theory?18. What is maximum shear stress?19. What is distortion energy?20. What is strain energy?21. What is fatigue?22. What is endurance stress?23. What is stress concentration?24. What are methods to avoid stress concentration?25. Explain material properties that are strength, stiffness, ductility,

malleability?26. What is factor of safety?27. What is working stress?28. What is resilience?29. What is proof stress?30. What is laminar flow, intermediate flow, turbulent flow?31. Define Reynolds number?32. Define Nusselt number?33. Explain with formula conduction, convection and radiation?34. Define heat flux.35. Define thermal conductivity, heat transfer coefficient with equations.36. Define steady state.37. Define convective heat flux.38. Define evaporation.39. Define film coefficient of heat transfer.40. What are the equations used for solving the pin film problems?41. Define thermal diffusivity.42. Define thermal resistance, contact resistance, convective thermal

resistance.43. Explain Fourier heart conduction?44. What is Newton’s law of heat transfer?45. Explain Stephan-Boltzman law of radiation.46. Explain rate of heat transfer through composite material with a heat

source?47. What is CST element?

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Dept. of ME

48. What is proportionality limit?49. Difference between structured & unstructured mesh?50. What is the difference between conventional method and finite element

method in the design process?51. What are the different types of modeling?52. Difference between wire frame modeling, surface modeling and solid

modeling?53. What are the advantages of solid modeling?54. What is the difference between constructive solid geometry and boundary

representation type solid modeling?55. What is meant by transformation? Give examples.56. What are the steps involved in finite element methods.57. What is the difference between 1d, 2d, 3d elements?58. Give examples for 2d, 3d elements.59. What is meant by discretisation?60. What is meant by shape function?61. Name commercially available FEM packages.62. What are the different modules available in FEM software?63. What is the role of preprocessor?64. What is the role of solver?65. What is the role of General Post processor?66. What is convergence and divergence?67. What is meant by stiffness matrix?68. What are the properties of a stiffness matrix?69. What is the difference between FDM and FEM?70. What is the difference between static and dynamic problem?71. What is the governing equation for structural problem?72. Give the equation for conservation of mass, moment and energy.73. Give examples for higher order elements.74. What are the different equations for Gaussian elimination method and

penalty method?

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ansys problems

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