Intermolecular Forces
In a solid, atoms are held in equilibrium positions by spring-like intermolecular forces. A deforming force changes these distances, leading to a restoring force.
Drag the blue atom to see the forces.
Elasticity & Plasticity
Apply a force to see how materials behave. Elastic bodies return to their original shape; plastic bodies deform permanently.
Types of Stress and Strain
Longitudinal
Changes length.
Volume (Bulk)
Changes volume.
Shear
Changes shape.
Interactive Stress-Strain Curve
Explore the Curve
Move the slider to see how a material behaves under increasing strain. Key points on the curve will be highlighted and explained here.
Elastic Hysteresis
For materials like rubber, the loading and unloading curves are different. The area between them represents energy lost as heat during deformation. This is crucial for applications like shock absorbers.
Hooke's Law Simulation
Elongation (): m
Force Constant (k): N/m
Within the elastic limit, stress is proportional to strain.
Young's Modulus (Y)
Determine the Young's Modulus of a wire. It's a measure of stiffness.
Stress (): Pa
Strain ():
Elongation (): mm
Thermal Stress
A rod fixed at both ends will experience stress if its temperature changes. Adjust the temperature to see the effect.
Status: Neutral
Stress: 0 MPa
Using Y_steel = 200 GPa,
Poisson's Ratio ()
When a material is stretched, it gets thinner. Poisson's ratio is the ratio of lateral strain to longitudinal strain.
Longitudinal Strain (): 0.00
Lateral Strain (): 0.00
Poisson's Ratio () ≈ 0.3 (for steel)
Bridge Beam Depression
The depression () of a beam depends on its dimensions, material, and the load.
Depression (): mm
Assuming L=20m, b=0.5m, d=1m, Y=200 GPa
Elastic Potential Energy
Energy stored in a stretched wire is the work done to stretch it. This is the area under the force-elongation graph.
Stored Energy (U): J