What is seismic fragility curves?
What is seismic fragility curves?
Seismic fragility curves are diagrams of probability of exceedance of a limit state, such as collapse, against a ground motion intensity measure, like spectral acceleration at the fundamental period.
What is seismic fragility analysis?
Basically, seismic fragility analysis is the comparison of seismic capacity and demand and to estimate whether the seismic capacity is exceeded for a well-defined performance level when the structural system is subjected to specified levels of ground motion intensity.
How do you create a fragility curve?
Generation of fragility curves in conventional methods involves development of large number of computational models that represent the inherent variation in the material properties of particular building type and its earthquake time history analyses to obtain an accurate and reliable estimate of the probability of …
What is P-Delta in Risa?
When a model is loaded, it deflects. This type of analysis is called “P-Delta” because the magnitude of the secondary moment is equal to “P”, the axial force in the member, times “Delta”, the distance one end of the member is offset from the other end. …
What is collapse mechanism?
What Does Collapse Mechanism Mean? By inserting a plastic hinge at a plastic limit load into a statically determinate beam, a kinematic mechanism permitting an unbounded displacement of the system can be formed. This is known as the collapse mechanism.
What is difference between plastic hinge and mechanical hinge?
Plastic hinges modify the behavior of structures in the same way as mechanical hinges. The only difference is that plastic hinges permit rotation with a constant resisting moment equal to the plastic moment Mp. At mechanical hinges, the resisting moment is equal to zero.
How do you calculate P-Delta effect?
P-delta is a moment found by multiplying the force due to the weight of the structure and applied axial load, P, by the first-order deflection, Δ or δ.
What is the collapse load?
The applied load at which a structure becomes a mechanism owing to the formation of sufficient plastic hinges for collapse to occur. …
What is collapse force?
Collapse force can be created by various external pressures, acting alone or in combination, including: • Hydraulic collapse, which can occur when the fluid outside the casing is higher or heavier than the inside fluid. • Impact or unsymmetrical loading resulting from improper placement of gravel pack.
