Equivalent modeling method of open thin-walled beam under action of transverse stiffening member

Satellite structures usually have a lot of open thin-walled beams under the action of transverse stiffening member. Transverse member is generally evenly distributed along the axial direction of the beam. Through the study of such structures, it is theoretically proved that the differential equation of vibration of this structure has the same form as the equation of ordinary open thin-walled beam. Therefore, equivalent calculation was carried out using the open thin-walled beam element. Three kinds of mathematical models of open thin-walled beams, finite element model, transfer matrix model and analytical model, were established. The equivalent cross-section parameters were identified using sequential quadratic programming. At the same time, the influence of different objective functions on the identification results was analyzed. And a method for estimating the initial parameters of the cross-section was presented. For the finite element model, the MATLAB and ABAQUS interactive parameters optimization method was proposed. A combination of both full advantages can quickly and efficiently optimize the cross-section parameters and this method has strong versatility. Finally, the correctness and accuracy of the equivalent modeling method are verified by experiments. The proposed equivalent modeling method can reduce more than 90% of the number of elements. By establishing the simplified model, the efficiency of the structural model updating and structure reanalysis can be greatly improved.