Unit 5 C2 Stress, Strain & Young's Modulus Flashcards
Which two properties of a material (for example, a wire) can change the value of the spring constant?
- The length of the wire/spring
- The thickness of the wire/spring
Define tensile strength
The ability to withstand being pulled/stretched
How is stress calculated and what are the units?
Define compressive strength
The ability to withstand being squashed/compressed
How is strain calculated and what are the units?
What is one similarity and one difference between Young’s Modules and the Spring Constant?
Similarity: They both correspond to the stiffness of a material
Difference: Young’s Modulus is NOT affected by dimensions of the material, but the Spring Constant is.
Sketch a graph that shows loading and unloading of masses on an INELASTIC material e.g. metal wire
Sketch a graph that shows loading and unloading of masses on an ELASTIC material e.g. rubber band
Sketch a graph that shows loading and unloading of masses on a PLASTIC material e.g. polythene bag
Which of the materials A,B,C or D is the strongest, and why?
A because it has the highest breaking stress point
Which of the materials A,B,C or D is the most brittle, and why?
A because it has the smallest/no plastic region
Which of the materials A,B,C or D is the most ductile, and why?
D, as it has the longest plastic region
Which of the materials A,B,C or D is the weakest, and why?
D, as it has the smallest Young’s Modulus
What is elastic hysteresis?
Elastic hysteresis refers to the energy loss that occurs when a material is subjected to cyclic loading and unloading.
What is represented by the difference between the loading and the unloading curves?
This area between the loading and unloading curve in the stress-strain diagram represents the energy lost in the form of heat, and this is known as the hysteresis loss.
