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Shanahan, T. G.

Publications and source records attributed to Shanahan, T. G..

A short cut integration scheme to determine the dynamic response of a launch vehicle with several payloads

The coupled base motion equations of a system composed of a launch vehicle and several payloads are derived. In previous work it was shown how the special form of these equations allow for a quick and accurate solution both for the response and the loads of the system. In this paper a short-cut version of this direct integration technique is presented and evaluated. The result is a method which, depending on the nature of the structure at hand, vasilates between a full-scale coupled base motion approach and an open loop base drive method. Although completely general, the presented technique is most effective when the number of interface degrees of freedom is relatively small compared to the overall number of degrees of freedom of the system. The S.T.S.-S.T.-O.M.S. Kit system is used as an illustrative example.

Engels, R. C.

Structural dynamics payload loads estimates: User guide

This User Guide with an overview of an integration scheme to determine the response of a launch vehicle with multiple payloads. Chapter II discusses the software package associated with the integration scheme together with several sample problems. A short cut version of the integration technique is also discussed. The Guide concludes with a list of references and the listings of the subroutines.

Shanahan, T. G.

An integration scheme to determine the dynamic response of a launch vehicle with several payloads

The coupled equations of motion of a system composed of a launch vehicle and multiple payloads are derived. In the process, it is shown how superfluous interface degrees of freedom on the booster side can be accommodated in the formulation. The discrete system equations are directly integrated, avoiding the solution of an expensive system eigenvalue problem. A modified Newmark-Chan-Beta numerical integration scheme is used to obtain the response. The unique form of the equations of motion allow for a quick and accurate solution both for the response and the internal loads. Although completely general, the presented technique is most effective when the number of interface degrees of freedom is relatively small compared to the overall number of degrees of freedom of the system. The technique is applied to the case of the S.T.S.-S.T.-OMS Kit system. Finally, an evaluation of the presented method is included.

Engels, R. C.