DULAY, Anthony Mark V.April 28, 20152012104035/ CE-3Engr. Ronnie Dy Hianto

Structureis a fundamental, tangible or intangible notion referring to the recognition, observation, nature, andpermanenceofpatternsand relationships ofentities. This notion may itself be an object, such as a built structure, or an attribute, such as the structure of society. It is an assemblage of a number of components like slabs, beams, columns,walls, foundations and so on, which remains in equilibrium. It has to satisfy the fundamental criteria of strength, stiffness, economy, durability and compatibility, for its existence. DIFFERENCE BETWEEN DETERMINATE AND INDETERMINATE STRUCTURES.Determinate structuresare analyzed just by the use of basic equilibrium equations. By this analysis, the unknown reactions are found for the further determination of stresses. Redundant or indeterminate structuresare not capable of being analyzed by mere use of basic equilibrium equations. Along with the basic equilibrium equations, some extra conditions are required to be used likecompatibility conditionsof deformations etc to get the unknown reactions for drawingbending moment and shear force diagrams. All the beams in which reactions of the supports may be determined by the use of equations of static equilibrium are known as statically determinate beams. The value of these reactions are independent of the deformation of the beam, while Indeterminate Structures is termed as statically indeterminate, if it cannot be analyzed from principles of statics alone, i.e.summation of forces horizontally, vertically and moments are equal to zero. A statically indeterminate structure may be classified as externally indeterminate, internally indeterminate and both externally and internally indeterminate. All the beams in which thenumberof reactions exceeds than the totalnumberof equations of static equilibrium are known as statically indeterminate beams. In these beams the static equations must be supplemented by the equation based upon the deformation of the beam.

ADVANTAGES OF INDETERMINATE STRUCTURES Smaller stresses

Greater stiffness

Redundancies

DISADVANTAGES OF INDETERMINATE STRUCTURES Stress due to support settlement Stresses due to temperature changes and fabrication error

ADVANTAGES OF DETERMINATE STRUCTURES Equilibrium conditions are fully adequate to analyze the structure Bending moment or shear force at any section is independent of the material property of the structure. The bending moment sheat force at any section is independent of the cross section or moment of inertia Temperature variations do not cause stresses No stresses are caused due to lack of fit Extra conditions like compatibility of displacements are not required to analyse the structure.DISADVANTAGES OF DETERMINATE STRUCTURES Sometimes it is not structurally efficient Unstable and there are chances that it will easily collapse