Dynamic Buckling Of Elastic-plastic Cylindrical Shells Under Coupling Loads

The stability of structure is a basic research task in solid mechanics all the time and isalso one of the difficult problems which need to be urgently solved in industry equipments,therefore the dynamic buckling is an important work which researchers concerned much. Thecylindrical shells are the most common structural forms, of which the buckling of thecylindrical shells is playing an important role in the structural stability. The researches of thebuckling in the past years have accelerated the development of the theories of structuralstability. Most researches are focus on cylindrical shells under single load .Because structuresusually get complex loads, it is necessary to study the situations when structures get compactloads.Impact load is a familiar dynamic load. It is more complex than static buckling for astructure under compact loads, because of such properties is dynamic , stress waves, thedistribution of the loads and time are all the influnces on the buckling under compact loads.For this reason, it is very difficulty to solve this problem in a numberical way.In this paper,we use the ANSYS finite element software to solve the dynamic buckling problem.In this paper, the fundamental problems of the dynamic buckling in cylindrical shells aretorsion impact and coupling impact. Assisted by ANSYS, the first step is to build the finitemodel of the cylindrical shells. The dynamic buckling in cylindrical shells is nonlinear.Because the compact loading on the structure is in- plane, a out-of-plane deflections necessaryto initiate buckling will not develop, and the analysis will fail to predict buckling behavior. Toovercome this problem, apply a small out-of-plane perturbation, such as modest temporaryforce or specified displacement, to begin the buckling response. A preliminary eigenvaluebuckling analysis of the structure is useful as predictor of the buckling mode shape beforetransient analysis.The analysis gives the buckling modes and the data of the nodes. It shows that the spreadand reflect of the stress waves have much relation to the dynamic buckling; the compact loadsinfluenced the buckling mode directly; and the loads forms on the structure and the materialdifference and the geometry of the structure are also effective parameters. Under the sametorsion compact load, the radical equal pressure also has some influence on the structure. Theresults of this paper help a lot for further investigation in similar problems, and give a correctdirection for further research.