Elastic Dynamic Time-history Analysis Of Non-classically Damping 3-Dimendion Structures

With the diversification of forms of the constructions, and based onthe purpose of seismic response reduction, the composite structures madeup of the materials with different damping properties have been builtmore and more, such as setting dampers in some parts of a structure, andsetting isolators between the structure and the foundation, and setting upsteel tower or steel roof truss on the top of reinforced concreteconstruction etc. This kind of constructions is the structures withnon-classically damping properties, so we cannot copy the usualcalculating way to analyze the dynamic response of the structures. An improved direct integration algorithm is given in the paper. Thealgorithm need not store damping matrix, and its calculating efficiency isonly a little less than the one of analyzing classically damping ratiostructure. If the number of the second kind of damping element iscomparatively less than the number of the whole structure element, itscalculating efficiency will be higher. The algorithm will decreasecalculating scale sharply and save time to take place of complex numbercalculating by directly computing linear equation group. And the wholecalculation is carried on in the real number field. So it is fit to spread andapply in the real project. The 2-dimension analysis of a structure is only fit for the regularstructure. If the structure is irregular, some assumption will be too muchimprecise and directly damage the 3-dimension dynamic properties of thestructure. Therefore it is necessary to carry on the 3-dimension dynamicanalysis to the irregular structure, especially the structure withnon-classically damping properties. So the writer works out thecalculating software for 3-dimendion structures about elastic dynamicanalysis of non-classically damping structures, and by comparing theresponse results of some examples in the paper with other inefficientalgorithms or software, the accuracy of this algorithm is demonstrated.The calculating software for 3-dimensional structures based on thisalgorithm meets the need of elastic dynamic analysis of compositestructures made up of materials with different damping properties. At lastby comparing the response results of some examples in the paper underthe earthquake wave with equivalent damping ratio, and single dampingratio, and real damping ratio etc, the result of the former two kind ofdamping ratio will tend towards waste of resource or insecurity, and thenput forward the things which should be paid great attention to in thestructure design.