Term: Strength of materials
**Material Strength and Properties**:
– Definition of material strength
– Importance of material properties and geometric properties
– Understanding material yield, ultimate strength, and fracture strength
– Material strength expressed in stress parameters
– Various strength parameters including fatigue strength and crack resistance
– Material strength and microstructure relationship
– Strengthening mechanisms like work hardening and solid solution strengthening
**Types of Loadings and Stress Terms**:
– Transverse loadings, axial loading, torsional loading, shear forces
– Compressive stress, tensile stress, shear stress
– Internal tensile and compressive strains in transverse loading
– Stress concentrations in materials loaded in tension
– Uniaxial stress formula
– Stress parameters for resistance
**Strain Parameters and Stress-Strain Relations**:
– Deformation, strain, deflection
– Elasticity, plasticity, brittle materials, ductile materials
– Young’s modulus and stress-strain relationship
– Strain energy per unit volume at the yield point
– Maximum Distortion Energy Theory (von Mises-Hencky theory)
– Strain energy and its significance in material behavior
**Design and Failure Analysis**:
– Ultimate strength, factor of safety, margin of safety
– Design stresses for static loading
– Fatigue failure and its causes
– Failure theories: maximum shear stress, normal stress, strain energy, distortion energy
– Fracture mechanics and its role in predicting material failure
– Practical considerations in material strength, especially under dynamic loading
**Applications and Theory**:
– Practical application of material strength in engineering
– Understanding loadings and stresses in structural members
– Design terms and criteria for engineered components
– Insights from failure theories and fracture mechanics
– Role of strain energy and distortion energy in material behavior
– Significance of stress-strain relations in material analysis
The field of strength of materials (also called mechanics of materials) typically refers to various methods of calculating the stresses and strains in structural members, such as beams, columns, and shafts. The methods employed to predict the response of a structure under loading and its susceptibility to various failure modes takes into account the properties of the materials such as its yield strength, ultimate strength, Young's modulus, and Poisson's ratio. In addition, the mechanical element's macroscopic properties (geometric properties) such as its length, width, thickness, boundary constraints and abrupt changes in geometry such as holes are considered.
The 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. An important founding pioneer in mechanics of materials was Stephen Timoshenko.