Where does MSE fit in the STEM ecosystem? Between Design-based disciplines and Discovery based disciplines. (Engineering
and Sciences) MSE blurs the line between discovery and design.
What do MSE's do? MSE provides "material constants" that other engineers use for design.
Material constant (property) An intrinsic property of a material that DOES NOT depend on size or shape. - i.e.
Resistivity is the material property, resistance is the performance parameter.
Performance Parameter The property of a component that is determined by the size, shape, and material
property (material constant). - i.e. Resistivity is the material property, resistance is
the performance parameter.
What categories of material properties do we care about? Mechanical, Chemical, Electrical, Thermal, Optical, Magnetic, and Cost
Losego's approach to material design Processing --> Structure --> Properties
Reasons to use a different material Original material may require more of a material (potentially costing more, weighing
more, etc), be more difficult or impossible to process/manufacture, and require a
trade-off with another necessary property
Load The force in a meterial
Tensile test A test that measures the stress-strain curve of a material.
Features of the stress strain curve Linear(elastic), non-linear(plastic) portion, yield stress, ultimate tensile strength,
maximum strain point
Elastic deformation A deformation that is reversible, meaning that when the load is removed, the
material will return to its original shape
Elastic Modulus aka Stiffness (E) The material's mechanical resistance to stretching, bending or flexing.
What does a low Elastic modulus mean? Low elastic modulus means that a material is easy to bend
Hooke's Law Equation σ=Eε
(lower case sigma) = (Uppercase epsilon)*(lowercase epsilon)
Stress = elastic modulus * strain
Elastic Modulus = slope of elastic portion of stress strain curve
, MSE 2001 Exam 1 | Practice Questions & Answers | 2026-2027
Stress equation σ=F/A
F= load
A = cross sectional area perpendicular to load direction
Strain equation ε=ΔL/L
strain = change in length/initial length
3 Types of elastic moduli Young's Modulus (E)
Shear Modulus (G)
Bulk Modulus (K)
For many materials E=K=8G/3
Young's Modulus An elastic modulus of a solid; the ratio of force per unit area to the stretch it
produces. The ability for a material to stretch. (Axial loading)
Shear Modulus A term describing a solid's resistance to shear stress, denoted by the letter S and
measured by the ratio of shear stress (F/A) to strain (x/h) or (W/L0)
Bulk Modulus A term that describes a substance's resistance to compression under pressure,
denoted by the variable B and measured by the ratio of stress (delta P) to strain
(delta V/V)
Plastic Deformation A permanent deformation of a material. Once the stress on a material exceeds the
yield stress, the material undergoes plastic deformation, and the material does not
return back to its original shape.
What happens when load is released after stress The descent of the stress strain curve after load is removed is parallel to the elastic
exceeded yield stress? portion of the curve, and it connects the x axis to the point at which load was
released.
Yield Stress (σy) aka Strength or Yield Stress The stress required to permanently deform a material. (Plastically deform a
material)
Ultimate Tensile Strength (σuts) aka Ultimate Strength The stress beyond which the material fails/fractures (the point of no return)
Maximum strain point. The stress starts going down after this.
Ductility (εf) The maximum amount of strain (%elongation) at failure
Poisson's Ration(v) The negative of the ration of the transverse (lateral) strain(εf) to the axial
(longitudinal) strain (ε)
Toughness of a material Energy per unit volume required to rupture or break the material. Area between the
strain axis, the stress strain curve, and the line descending from the fracture point
which is parallel to the elastic portion of the stress strain curve
What are characteristics of a tough material? High strength and ductility