Civil Engineering/moment redistribution
First,Sorry for the inconvenience and my long questions ( the first two question are more important than others ) :
1- do ( etabs or sap or safe) have option for moment redistribution) ? if they have it , please tell me where it is .
2-Is not it very difficult to redistribute the moments for a full tower - as example - and design manually after analyzing in Etabs ? ! Is not there certain conditions and considerations enable me to design in etabs without redistribution of moments ?
3 - in "Ultimate Strength Design" we design for moment less than Mu and Mp for all sections , that means there is no possibility for hinges to be formed thus we do not need to redistribute moment , isn't it right ?
4 - After analysis in Etabs , if we design without redistribution of moments , the results will be acceptable ?
Thank you very much
1- You Can do a push over analysis assuming nonlinear links at girders ends. It is not very hard to do exercise. You can perform it for entire structure automatically. I don't like a single file analysis because you may need to investigate in several views and have a sensitivity analysis.
2- After all you may know that redistribution of moment would provide you with a more efficient and economical design but you are not obligated to do .
3- The redistribution of moments is not a state which happens but it is a scenario to tune the margin of safety. The actual extreme load should me less than Mu , it doesn't mean that plastic behavior is not conceivable. But in any situation it is you as a designer that may decide about to have more advanced design or not.
4- You may guess that yes , may be it is more than acceptable to design without a moment redistribution, because this is your own art to choose your way to analysis and design provided that you don't pass the red boundaries of codes.