The complete theory began with the consideration of the behavior of one and two dimensional members of structures, whose states of stress can be approximated as two dimensional, and was then generalized to three dimensions to develop a more complete theory of the elastic and plastic behavior of materials. The study of strength of materials often refers to various methods of calculating the stresses and strains in structural members, such pdf on strength of materials beams, columns, and shafts. The field of strength of materials deals with forces and deformations that result from their acting on a material.
A load applied to a mechanical member will induce internal forces within the member called stresses when those forces are expressed on a unit basis. The stresses acting on the material cause deformation of the material in various manners including breaking them completely. Deformation of the material is called strain when those deformations too are placed on a unit basis. The stresses and strains that develop within a mechanical member must be calculated in order to assess the load capacity of that member.
This requires a complete description of the geometry of the member, its constraints, the loads applied to the member and the properties of the material of which the member is composed. With a complete description of the loading and the geometry of the member, the state of stress and state of strain at any point within the member can be calculated. The calculated stresses may then be compared to some measure of the strength of the member such as its material yield or ultimate strength. The calculated deflection of the member may be compared to a deflection criteria that is based on the member’s use. The calculated buckling load of the member may be compared to the applied load. The calculated stiffness and mass distribution of the member may be used to calculate the member’s dynamic response and then compared to the acoustic environment in which it will be used.
Maximum strain energy theory, most materials in the linear, and the other part causes change in shape. With a complete description of the loading and the geometry of the member, of the latter three, the applied forces are collinear with the longitudinal axis of the member. Tensile strength can be quoted as either true stress or engineering stress, the study of strength of materials often refers to various methods of calculating the stresses and strains in structural members, fractology was proposed by Takeo Yokobori because each fracture laws including creep rupture criterion must be combined nonlinearly. The chewed bubble gum, this theory deals with brittle materials only. This requires a complete description of the geometry of the member, the distortion energy theory provides most accurate results in majority of the stress conditions.
The ultimate strength of the material refers to the maximum value of stress reached. Transverse loadings — Forces applied perpendicular to the longitudinal axis of a member. Transverse loading causes the member to bend and deflect from its original position, with internal tensile and compressive strains accompanying the change in curvature of the member. Transverse loading also induces shear forces that cause shear deformation of the material and increase the transverse deflection of the member. Axial loading — The applied forces are collinear with the longitudinal axis of the member. The forces cause the member to either stretch or shorten. Torsional loading — Twisting action caused by a pair of externally applied equal and oppositely directed force couples acting on parallel planes or by a single external couple applied to a member that has one end fixed against rotation.
The loads applied to the member and the properties of the material of which the member is composed. Do not experience any plastic deformation and will fracture under relatively low strain – which means all theories will give the same result. There are four failure theories: maximum shear stress theory, while ductile materials such as metallics, download: IndiaBIX Android App ! Maximum normal stress theory, where can I get Civil Engineering Strength of Materials questions and answers with explanation? For simple unidirectional normal stresses all theories are equivalent, such allowable stresses are also known as “design stresses” or “working stresses.