Mechanics of Materials

Bearing Stress – Stress produced by the pressure or intensity of a force at the contact point of two bodies or structural members
Breaking Point – The maximum point in which a material can elongate; the point at which a material fails or breaks when subjected to a stress
Compression Force – A force caused from the compacting or pushing in of structural fibers
Creep – Deformation of a structure over an extended time
Elastic Deformation – Temporary deformation of a material where the material subjected to a load or force returns to its original dimensions once the load or force is removed
Flexure – The bending of a material under load application
Hook’s Law – Law discovered by Robert Hook in 1678 that describes the linear and proportional
relationship of stress and strain in elastic materials subjected to moderate loading.
Modulus of Elasticity (Young’s Modulus) – A measure of stiffness of a material that is measured by the slope of the elastic portion of the stress-strain curve
Normal (Axial) Stress – Stress produced by a tension or compression force acting perpendicular to the surface area under stress
Plastic Deformation – Deformation that remains permanent in a material subjected to load or force and remains in place even after the load or force is removed
Shear Force – An effect that produces shifting of horizontal or vertical parallel plains of a material
Shear Stress – Stress that is produced by a force applied parallel to the stressed area. Shear stress is calculated by dividing the shear force by the parallel area resisting the force.
Stiffness – The ability of a material to withstand deformation under stress
Strain – The deformation of the physical dimension of a body under stress
Strain Hardening – A stage beyond yield stress where steel goes through structural changes that result in increased strength and resistance to further deformation
Stress – Describes the intensity of a force and is expressed by the amount of force acting per unit of area
Stress Concentration – The accumulation of stress on a small section or area of an object
Tension Force – A force that pulls or stretches the fibers of a material away from each other
Thermal Strain – The change in material dimensions as a result of temperature changes
Thermal Stress – The expansion and contraction of a material due to thermal change
Torsion – The twisting and distortion of a material’s fibers in response to an applied load
Ultimate Stress – The maximum stress level of a material at which it breaks or ruptures
Yield Stress – The point at which stress causes a material to permanently deform