Materials-Analyzing stress-strain graphs

• What is the definition of strain?

  Change in shape or size when stress is applied
• What does Young's Modulus indicate about a material?

  How stiff a material is
• What is the Yield Strength at 0.2% Offset?

  The Yield Strength at 0.2% Offset is the stress at which the material exhibits a permanent deformation of 0.2% of the original length.
• What happens to the relationship between stress and strain beyond the proportional limit?

  They are no longer directly proportional
• What law is no longer obeyed beyond the proportional limit?

  Hooke's law
• What is the 2nd value mentioned in the image?

  Proportional Limit
• How is strain calculated?

  Strain = (new length - original length)/original length
• What are the key differences between stress and strain?

  • Stress: Force per unit area
  • Strain: Change in shape or size
  • Stress measures resistance; strain measures deformation
• What is the 3rd value mentioned in the image?

  Yield Strength
• What does a higher Young's Modulus indicate?

  A stiffer material
• What is the definition of Young's Modulus?

  Ratio of stress to strain in elastic region
• How does the stress-strain graph relate to Young's Modulus?

  It shows the ratio of stress to strain
• How is stress calculated?

  Stress = force/area
• What is the 1st value mentioned in the image?

  Elastic Region Modulus
• How does the "True Stress Strain Curve" differ from the "Engineering Stress Strain Curve"?

  • True Stress Strain Curve accounts for changes in cross-sectional area during deformation
  • Engineering Stress Strain Curve uses the original cross-sectional area
  • True Stress Strain Curve provides a more accurate representation of material behavior
• What occurs to the material in the plastic region when the force is removed?

  It doesn't fully recover its shape
• What is the Proportional Limit?

  The Proportional Limit is the maximum stress at which the stress-strain relationship remains linear, beyond which the material begins to deform plastically.
• What are the two regions of material behavior?

  Elastic region and plastic region
• What does the stress-strain graph show in hysteresis?

  It creates a loop during loading and unloading
• What does the proportional limit mark on the graph?

  The end of the perfectly elastic region
• What is the key difference between the "Elastic Limit" and the "Yield Strength" on the Stress Strain Curve?

  Elastic Limit is the maximum stress before permanent deformation, Yield Strength is the stress at which plastic deformation begins
• What is hysteresis in materials?

  Behavior differs during loading and unloading
• What is the definition of Young's Modulus?

  Young's Modulus is the ratio of the rise in stress to the corresponding strain in the elastic portion of the stress-strain curve.
• What is the point on the stress-strain curve where the material starts to deform plastically?

  Yield Strength
• If a rubber band stretches from 50 mm to 60 mm, what is the strain?

  0.2
• What is the Yield Strength?

  The Yield Strength is the stress at which the material begins to deform plastically and no longer returns to its original shape and size when the load is removed.
• What is the 4th value mentioned in the image?

  Yield Strength at 0.2% Offset
• What is the name of the curve shown in the image?

  Stress Strain Curve
• How does the Coercivity of the material affect its magnetic properties?

  Coercivity determines the material's resistance to demagnetization
• What is the formula to calculate strain?

  Strain = Change in Length / Total Length
• What is the key difference between the "Elastic Limit" and the "Yield Strength" on the Stress Strain Curve?

  Elastic Limit is the maximum stress before permanent deformation, Yield Strength is the stress at which plastic deformation begins
• What occurs when you let go of a stretched spring?

  It should go back to its original shape
• What is the significance of the elastic and plastic regions in the stress-strain curve?

  • Elastic region: Material deforms reversibly, can return to original shape/size
  • Plastic region: Material deforms irreversibly, undergoes permanent changes
• What does Young's Modulus indicate about a material?

  It measures the material's stiffness
• What is the role of stress-strain graphs in design safety?

  They help calculate safe stress limits
• What is the relationship between the Rise, Run, and Slope of the stress-strain curve?

  • Rise = Young's Modulus
  • Run = Strain
  • Slope = Rise / Run = Young's Modulus
• What does the elastic limit represent in material science?

  It indicates the safe working limit of a material
• What happens to the shape of a material in the plastic region?

  It stays deformed
• What does hysteresis indicate about a spring's behavior?

  It has a memory of being stretched
• What does the Stress Strain Curve show?

  The relationship between stress and strain in a material