2.5.6 - Stress and Strain

What characterizes uniaxial loading on a solid metal bar?

• Forces acting perpendicular to the bar's axis.

• Forces acting along the same axis, pulling or pushing the bar.

• Forces applied from multiple directions simultaneously.

• Forces that cause the bar to bend or twist.

What is stress in the context of a body responding to external loads?

• A measure of the body's overall deformation.

• The total external force applied to the body.

• A quantity describing the distribution of internal forces within a body.

• The rate at which a body changes its shape.

What are the SI units for stress?

• Pounds per square inch (lb/in^2)

• Newtons per meter (N/m)

• Pascals (Pa)

• Kilograms per cubic meter (kg/m^3)

How is normal stress calculated?

• Applied force multiplied by the cross-sectional area.

• Applied force divided by the cross-sectional area.

• Change in length divided by original length.

• Original length multiplied by the applied force.

What is the sign convention for tensile and compressive stresses?

• Tensile stresses are negative, compressive stresses are positive.

• Both tensile and compressive stresses are always positive.

• Tensile stresses are positive, compressive stresses are negative.

• The sign depends on the material's properties.

What characteristic defines the elastic region of a stress-strain diagram?

• Deformations are permanent.

• The relationship between stress and strain is linear.

• The material breaks easily.

• The material undergoes significant plastic deformation.

What is Young's modulus?

• The force required to break a material.

• The ratio between stress and strain in the elastic region.

• The maximum stress a material can withstand before permanent deformation.

• The amount of energy a material can absorb before fracturing.

What happens to deformations in the plastic region of a stress-strain diagram when the load is removed?

• They are fully reversed.

• They become permanent.

• The material returns to its original shape.

• The material's stiffness increases.

What type of stress acts parallel to a surface?

• Normal stress

• Tensile stress

• Shear stress

• Compressive stress

How is average shear stress calculated?

• Applied force multiplied by cross-sectional area.

• Applied force divided by cross-sectional area.

• Change in length divided by original length.

• Stress divided by strain.