ABSTRACT
Inordertodesignasteelorcompositestructure,thestructuraldesignermustestimatethe designactions(loads)actingonthestructure.Designactionsonsteelandcompositestructuresmaybedividedintopermanentactions,imposedactions,windactions,snowactions, earthquakeactionsandotherindirectactionscausedbytemperature,foundationsettlementandconcreteshrinkages.Thestructuraldesignermustdeterminenotonlythetypes andmagnitudesofdesignactionswhichwillbeappliedtothestructurebutalsothemost severecombinationsofthesedesignactionsforwhichthestructuremustbedesigned.The combinationsofdesignactionsareundertakenbymultiplyingthenominaldesignactions using load factors.
