Chapter 1 Flashcards
What are the most fundamental concepts in mechanics of materials
Stress and Strain
What is a Prismatic Bar?
It is a straight structural member having the same cross section throughout its length.
What is an Axial Force?
It is a load directed along the axis of the member, resulting in either tension or compression in the bar.
What are the units of Stress?
Stress has the units of force per unit area.
What is tensile stress?
A “Stretching” force/
What is compressive stress?
A “compressive” force.
When is a stress considered a normal stress?
When the stress acts in a direction perpendicular to the cut surface.
Describe the sign convention used for tensile and compressive stresses.
Tensile stresses are considered positive, and compressive stresses are considered negative.
In general, the elongation of a segment is equal to what?
Its length divided by the length L and multiplied byt he total elongation δ.
What is strain?
It is the elongation of a segment per unit length. denoted by epsilon.
Strain
ε =
δ/L
What is shear stress?
A stress that acts tangential to the surface of the material.
What is average bearing stress?
It is calculated by dividing the total bearing force Fb by the bearing area Ab .
What is bearing area?
The bearing area is defined as the projected area of the curved bearing surface.
What is average shear stress?
The average shear stress on the cross section of a bolt is obtained by dividing the total shear force V by the area A of the cross section on which it acts.
