bruce mayer, pe licensed electrical & mechanical engineer bmayer@chabotcollege

[email protected] • ENGR-10_Lec-09_Chp6_Population_Energy.ppt1

Bruce Mayer, PE Engineering-10: Intro to Engineering

Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engineering 10

Chp.10 Chp.10 Computer Computer

ToolsTools



Mr. Huezo’s Chevy 350 CID EngineMr. Huezo’s Chevy 350 CID Engine



Engineering SoftwareEngineering Software

Our Guest Speakers have Mentioned Several SPECIALIZED Computer Tools Used by Engineers• Pro-E (CAD)

• AutoCAD (CAD)

• MATLAB

• ANSYS FEA

• MicroStation XM(CAD)



Chabot Engineering SoftwareChabot Engineering Software

Chabot Engineering Students Learn TWO pieces of special Software

MATLAB

AutoCAD

MATLAB is a MATH-Processor AutoCAD is a BLUEPRINT-Processor



MATLAB EnvironmentMATLAB Environment

TWO Interaction Modes• INTERACTIVE

– Type in the COMMAND WINDOW

– Often Called a Command-Window “Session”

– Interaction is NOT Saved to Disk

• STORED → Two Types– SCRIPT Files

– FUNCTION Files



Command Window SessionCommand Window Session



Example Cmd Window SessionExample Cmd Window Session>> %Use MATLAB As Calculator

>> 17*19

ans =

323

>> 77/19 -4.3

ans =

-0.2474

>> 64^(1/3) + 32^0.2

ans =

6

>> (7+11)*2.5

ans =

45

>> L = 14.4

L =

14.4000

>> W = 13.3

W =

13.3000

>> Area = L*W

Area =

191.5200



A sim

ple M

AT

LA

B F

ileA

simp

le MA

TL

AB

File

% Bruce Mayer, PE% ENGR10 Demo * 18Oct09% file = E10_Demo_0910.m%% Define Anon FcnE10fcn = @(x) exp(x/7)-5*cos(x)%% plot the fcnfplot(E10fcn, [0 10]),grid%% find roots between 0-10R1 = fzero(E10fcn, 2)R2 = fzero(E10fcn, 5)R3 = fzero(E10fcn, 7)



The Function GraphThe Function Graph

0 1 2 3 4 5 6 7 8 9 10-4

-2

0

2

4

6

8

10



Electric-DiPole E-Field VisualizationElectric-DiPole E-Field Visualization

x

y

r2r2r1 dy

dx1

dx2

Point at (x,y)

x-0.3

x-(-0.3) = x+0.3

2

2

1

1

04

1

r

q

r

qV

E-Field Governing Equation



The Distance CalcsThe Distance Calcs

Using Pythagorean Theorem

222211 3.0 yxdydxr

22

2

222222

3.0

3.0

yxr

yxdydxr



Meshc Plot MeshGridMeshc Plot MeshGrid

-0.4

-0.2

0

0.2

0.4

-0.4

-0.2

0

0.2

0.40

20

40

60

80

X-distance

2 Point-Charges Electical Field

Y-distance

Ele

ct.

Pot

entia

l (V

)



surf Plot by MeshGridsurf Plot by MeshGrid

-0.4

-0.2

0

0.2

0.4

-0.4

-0.2

0

0.2

0.410

20

30

40

50

60

70

80

X-distance

2 Point-Charges Electical Field

Y-distance

Ele

ct.

Pot

entia

l (V

)



Th

e Mesh

Grid

Plo

tT

he M

eshG

rid P

lot

% Bruce Mayer, PE * 15Oct09 * ENGR25 % file = Prob5_57_Point_Charges_meshgrid_Plot_0910.m% Surface Plot eField from two Point Charges%% CLEAR out any previous runsclear% The Constant Parametersq1 = 2e-10; q2 = 4e-10; % in Coulombsepsilon = 8.854e-12; % in Farad/m%% Note the distances, r1 & r2, to any point(x,y) in the field by pythagorus% * r1 = sqrt((x-0.3)^2 + y^2)% * r2 = sqrt((x+0.3)^2 + y^2)%% Construct a 50x50 mesh[X Y] = meshgrid(-0.25:0.010:0.25);%% find r1 & r2 by pythagorus and array-opsr1 = sqrt((X-0.3).^2 +Y.^2); % note dots used with array operationr2 = sqrt((X-(-0.3)).^2 +Y.^2); % note dots used with array operation% use vectors r1 & r2, and array ops to find VV = (1/(4*pi*epsilon))*(q1./r1 +q2./r2);%surf(X,Y,V), xlabel('X-distance'), ylabel('Y-distance'),... zlabel('Elect. Potential (V)'), title('2 Point-Charges Electical Field'),... grid on%disp('Showing SURF Plot - Hit ANY KEY to continue')pausemeshc(X,Y,V), , xlabel('X-distance'), ylabel('Y-distance'),... zlabel('Elect. Potential (V)'), title('2 Point-Charges Electical Field'),... grid ondisp('Showing meshC Plot - Hit ANY KEY to continue')pausemeshz(X,Y,V), , xlabel('X-distance'), ylabel('Y-distance'),... zlabel('Elect. Potential (V)'), title('2 Point-Charges Electical Field'),... grid on



AutoCAD DemoAutoCAD Demo

Make 2D & 3D CAD Drawing for

5 inches

Front View



Classic “B

lueP

rint”

Classic “B

lueP

rint”



3D R

epresen

tation

3D R

epresen

tation



AutoCAD 3D DemonstrationAutoCAD 3D Demonstration

E10_Pipe_Support_3D_0910.dwg



All Done for TodayAll Done for Today

MATLABKleinBottle

bruce mayer, pe licensed electrical & mechanical engineer bmayer@chabotcollege

Documents