PSAD CELE TERMS

Strain energy 

It refers to the energy stored in a material due to its deformation 

Elasticity 

It refers to the property of a material which makes it return to its original state when the load is removed. 

Ductility 

It refers to the ability of a material to deform in the plastic range without breaking. 

Hardness 

It refers to a material’s resistance to indentation. 

Shear wall 

It refers to a wall designed to resist lateral forces acting in its own plane, typically wind and seismic loads.

Center of gravity 

It refers to the point where the object “suffers” no torque by the effect of the gravitational force acted upon it. 

Center of stiffness 

It refers to the point point through which the resultant of the restoring forces of a system acts. 

Design Seismic Base Shear 

It refers to the total design lateral force at the base of a structure.

Story displacement 

It refers to the lateral displacement of the story relative to the base 

Out-of-plane offsets 

It refers to the discontinuities in a lateral force path 

Torsional shear stress 

It refers to the shear stress that occurs when the structure’s center of mass does not coincide with its center of rigidity 

Resonance 

It refers to the phenomenon that occurs when a building period coincides with the earthquake period.

Natural period 

It refers to the time period of undamped free vibration of a structure.

Damping 

It refers to the rate at which natural vibration is absorbed. The effect of internal friction, imperfect elasticity of material, slipping, sliding, etc in reducing the amplitude of vibration  

Epicenter 

It refers to the geographical point on the surface of earth vertically above the focus of the earthquake.

Focus

It refers to the origin/source of the elastic waves inside the earth which cause shaking of ground due to earthquake. 

Intensity

It refers to the measure of the strength of shaking during the earthquake 

magnitude

It refers to the measure of energy released in an earthquake

Weak Storey Irregularity 

It refers to the condition is one in which the storey lateral strength is less than 80 percent of that in the storey above.