BME 231- Exam 3 PIL Review Questions and Answers Graded A+
What are deformable bodies? - Answers Bodies which do not obey rigid body assumption- two
points can move relative to one another under a given load.
Forces in the x direction are called what? - Answers Axial/normal forces
Forces in the y and z direction are called what? - Answers Shear forces
Moments in the x direction are called what? - Answers Twisting torque
Moments in the y and z direction are called what? - Answers Bending moments
Equation for stress? - Answers Force/Area
Equation for strain? - Answers change in length/original length
Equation to relate stress and strain? - Answers Stress = E*Strain
What does stress allow us to do? - Answers Normalize force to an area over which it is applied.
What does strain allow us to do? - Answers Normalize a displacement to a geometry.
What does F represent on a Stress-Strain diagram? - Answers The point of failure.
What does U represent on a Stress-Strain diagram? - Answers The ultimate stress/strength. The
maximum stress which the material experiences before failure.
What does Y represent on a Stress-Strain diagram? - Answers The yield point/stress. It is the
stress beyond which there is a "substantial" change in deformation per stress.
What does E represent on a Stress-Strain diagram? - Answers The elastic limit. The point at
which we begin to experience plastic deformation.
What does P represent on a Stress-Strain diagram? - Answers The proportionality limit. Where
the relationship between stress and strain stops being linear.
What does the linear slope on a stress-strain diagram give us? - Answers Young's Modulus (E)
What is the difference between elastic and plastic deformation? - Answers Elastic deformation
can be recovered fully after releasing the load, whereas plastic deformation is permanent.
What are the two ways to represent ductility? - Answers 1) Strain at fracture
2) % reduction in area
What makes a material homogenous? - Answers If it is the same throughout.
What does isotropic behavior mean? - Answers Same behavior when loaded in any direction.
What are deformable bodies? - Answers Bodies which do not obey rigid body assumption- two
points can move relative to one another under a given load.
Forces in the x direction are called what? - Answers Axial/normal forces
Forces in the y and z direction are called what? - Answers Shear forces
Moments in the x direction are called what? - Answers Twisting torque
Moments in the y and z direction are called what? - Answers Bending moments
Equation for stress? - Answers Force/Area
Equation for strain? - Answers change in length/original length
Equation to relate stress and strain? - Answers Stress = E*Strain
What does stress allow us to do? - Answers Normalize force to an area over which it is applied.
What does strain allow us to do? - Answers Normalize a displacement to a geometry.
What does F represent on a Stress-Strain diagram? - Answers The point of failure.
What does U represent on a Stress-Strain diagram? - Answers The ultimate stress/strength. The
maximum stress which the material experiences before failure.
What does Y represent on a Stress-Strain diagram? - Answers The yield point/stress. It is the
stress beyond which there is a "substantial" change in deformation per stress.
What does E represent on a Stress-Strain diagram? - Answers The elastic limit. The point at
which we begin to experience plastic deformation.
What does P represent on a Stress-Strain diagram? - Answers The proportionality limit. Where
the relationship between stress and strain stops being linear.
What does the linear slope on a stress-strain diagram give us? - Answers Young's Modulus (E)
What is the difference between elastic and plastic deformation? - Answers Elastic deformation
can be recovered fully after releasing the load, whereas plastic deformation is permanent.
What are the two ways to represent ductility? - Answers 1) Strain at fracture
2) % reduction in area
What makes a material homogenous? - Answers If it is the same throughout.
What does isotropic behavior mean? - Answers Same behavior when loaded in any direction.
