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Pepito
Posts:
17
Registered:
12/13/04


Complete Quadratic Combination rule CQC
Posted:
Apr 5, 2005 1:28 PM


The well kwon CQC (complete quadratic combination rule) method give the expected maxima peak value for a variabile. The classical use of the formula (in my field of interest) is the evaluation of the expected value of a action/displacement using modal analisys (Eg DesignShear= ( sum i=1Nmodes sum j=1=Nmodes Pij Vi Vj )^1/2 where Pij is the CQC correlation factor). Suppose you work whit two linearly correlated variables (for instance Normal Force and Bending Moment in a column or main stress in a membrane ec...) The CQC method give you the expected maxima value for the two actions say V1max e V2max but, this two value are uncorrelated in time. For design purpose i need to use this values coupled and i think is not correct to use the maxima value V1max e V2max. The question is: Knowing the values Vimax (or V2max) what is the correct maximum expected value for the V21max (or V12max?). In other hand what is the correct pair of design actions Vimax , V2(V1max) and V2max, V1(V2max)? Thanks for your suggestions and sorry for the poor english.....



