MS&E #6 Mechanical Properties

21 flashcards · Physics · by Kristóf Nagy

1. Poisson's ratio

   Describes the relationship between the transverse strain and axial strain of a material undergoing elastic deformation, indicating the degree of lateral contraction caused by axial extension.

2. design stress

   The calculated stress level that a material is allowed to experience in a specific application, determined by multiplying the calculated nominal stress by a safety factor that accounts for sources of uncertainty and risk.

3. ductility

   The ability of a material to deform significantly before rupturing, allowing it to absorb energy and undergo plastic flow.

4. elastic deformation

   Occurs when a material responds to an external force by changing shape temporarily, returning to its original shape once the force is removed.

5. elastic recovery

   Describes the ability of a material to recover its original shape and size after experiencing elastic deformation.

6. engineering strain

   Defined as the partial derivative of the deformation gradient tensor with respect to spatial coordinates, representing the infinitesimal strain caused by a differential change in displacement.

7. engineering stress

   Represents the force acting on a unit area of a material, accounting for both the axial force and the cross-sectional area.

8. hardness

   A measure of a material's resistance to localized deformation or indentation, quantified by the depth or size of the indentation left by a sharp object.

9. modulus of elasticity

   A measure of a material's stiffness, describing the ratio of stress to strain in the elastic regime.

10. plastic deformation

    Occurs when a material experiences permanent deformation due to external forces, exceeding the elastic limit and causing irreversible changes in shape and size.

11. proportional limit

    Marks the highest stress level at which a material exhibits perfectly linear elastic behavior, before entering the plastic deformation regime.

12. resilience

    Represents the ability of a material to absorb energy and return to its original shape after experiencing elastic deformation.

13. safe stress

    The maximum allowable stress level for a material in a specific application, determined by dividing the yield strength by a safety factor that accounts for sources of uncertainty and risk.

14. shear

    Refers to the sliding motion of two adjacent layers of a material relative to each other, caused by an external force.

15. tensile strength

    Represents the maximum stress that a material can withstand in tension before failing, providing a measure of its overall strength and durability.

16. toughness

    Describes a material's ability to resist fracture or crack propagation, quantified by the energy required to initiate and propagate cracks.

17. true strain

    A dimensionless measure of deformation, defined as the integral of the partial derivative of the deformation gradient tensor with respect to spatial coordinates, representing the cumulative strain experienced by a material throughout its history.

18. true stress

    A measure of the internal force exerted by a material, corrected for changes in cross-sectional area due to deformation, and defined as the product of the true strain and the current cross-sectional area.

19. yielding

    Refers to the onset of plastic deformation in a material, marked by the appearance of permanent deformation or a sudden drop in stress.

20. yield strength

    Represents the maximum stress that a material can withstand in tension before experiencing permanent deformation, serving as a key indicator of its strength and ductility.

21. anelasticity

    Refers to the time-dependent response of a material to external forces, where the material exhibits delayed elastic strain in addition to immediate elastic strain.