It's when a material gets bent, squashed or otherwise changes shape to the point where it can't change back when the load is removed.
plastic behavior is the region where we have the non linear curve and upon unloading the shape can not be recovered.at this region,the stress is not directly proportional to strain i.e Hooke's law is not obeyed
The formula to calculate total strain is: Total Strain Elastic Strain Plastic Strain. Elastic strain is the initial deformation of the material under load, while plastic strain is the permanent deformation after the material reaches its yield point.
To find stress and strain in a material under load, you can use the formulas: stress force applied / cross-sectional area of the material, and strain change in length / original length of the material. These calculations help determine how the material deforms under the applied load.
Yield stress is the point at which the material is no longer linear under load; the material starts to become plastic and when unloaded will not return to its original length. Typically the yield point is defined as 0.2% offset - the value of strain that remains in the part after unloaded
Stiffness of a material is a measure of its resistance to deformation when subjected to an applied load. It indicates how much a material will deform under a given load. Materials with high stiffness will deform less under load, while materials with low stiffness will deform more.
Residual indentation refers to the permanent deformation or mark left on a material's surface after an external force or load has been removed. This occurs when the material does not fully recover its original shape, often due to plastic deformation. Residual indentation is commonly assessed in materials testing to evaluate properties such as hardness and ductility. It can provide insights into the material's behavior under stress and its long-term durability.
Springback means Recovered elastic strain on material after the load is removed.
Toughness from impact test is a measure of a material's ability to absorb energy during sudden loading, while toughness from tensile test is a measure of a material's ability to deform plastically before fracturing under a slowly applied load. Impact toughness is important for assessing material behavior under dynamic loading conditions, while tensile toughness provides insight into material behavior under static loading conditions.
the beam will sag downwads
When the load hanging on a material is doubled, the young modulus of elasticity remains constant. Young's modulus is a material property that measures its stiffness and is independent of the applied load. It represents the material's ability to deform elastically under stress without permanent deformation.
The toe region of a curve represents the initial low-velocity, elastic deformation phase where stress and strain are directly proportional. It is the beginning segment of the stress-strain curve when a material starts to deform under load but before significant plastic deformation occurs. The toe region is where the material's structure begins to reorganize and align, allowing for further plastic deformation.
The opposite of elastic is inelastic, where a material cannot stretch and rebound. A material without this quality could be "inflexible" (rigid, stiff) or one that did not rebound, termed "plastic" (deformable).Elastic suggests that the material recovers its original shape after an applied load is removed. Plastic means that it doesn't recover its shape. Steel is an example of an elasticmaterial, when it is loaded within its capacity. It becomes plastic if it is overloaded. Concrete can be considered an elastic material only in compression.