Static And Dynamic Analysis Of Thin-Walled Bar With Closed Profile By Fem

Thin-walled bar with closed profile has the advantage of stronger torsional rigidity and can display the performance of characteristic of materials fully, therefore, it obtains the widespread application in the practical engineering. Compared to common member, because of the special deformation behaviour, it is very important to set up the analytic solution and numerical analysis model.The theory of the thin-walled bar with closed profiles with restrained torsion based on the assumption of unyielding profile, which has the extensive application both in the static analysis and dynamic analysis.This paper studies the numerical method for thin-walled bar with closed profile under the application of restrained torsion in two ways, according to these, the torsion differential equations and the analytic solution are developed. Based on the variational principle of the thin-walled bar and the Hermite functions, the one-dimensional discrete finite member element method for numerical models analysis of box bar is proposed. Meanwhile, the effect of distortion of cross section and the condition under complex load are both considered.This paper also includes the effects of shear lag and distortion on thin-walled box bar under complex load. The analysis model of thin-walled bar is formulate-d by one-dimensional discrete finite member element method. The results obtained with one-dimensional computation model are compared with ANSYS model and elementary theory of beam.The numerical dynamic analysis model of the thin-walled bar is formulated by one-dimensional discrete finite member element method which is based on Hamilton Theory, and the FORTRAN programs are created to calculate the dynmaic characteristics of thin-walled bar.The results obtained with one-dimensional element method in this paper are compared with 2D-model, which agrees well with fewer unknowns and higher accuracy.