Overstrength Factor

[hjin25]

Overstrength factor is basically expected strength during inelastic or actual response of structure. When do I use this? ie. for element design or overall system design?

ASCE provides values for overstrength factor for a SYSTEM. Is this load combination used when designing an element as well as global system?

Im just confused as to the difference between earthquake load effect vs. overstrength factor in load combinations. Thanks

 

[YMZ PE]

Overstrength factor represents the strength of a system, not an individual element. Think of it as proportional to the factor of safety of the system. The more ductile and redundant your system, the higher the overstrength/factor of safety provided.