| As most of the engineering structure design will inevitably be affected by stochastic loads, such as earthquake, wind, waves and so on, it is necessary to make the effect of these loads into consideration in structure optimization design. In recent years, since the time domain explicit method has been found having the advantage of high speed and high accuracy in issue of stochastic response, it is studied and applied by more and more scholars. The main objective of this thesis is based on the method of stochastic response sensitivity analysis of time domain explicit method, combined with effective optimization algorithm, and applied them to the shape of truss structure and the problem of topology optimization. The research shows that the method has good feasibility and practicability, and has broad application prospects. The following is the specific research content of this article:Firstly, based on the idea of time-domain explicit method, the present study adopted two different integration formats to derive the time domain representation of stochastic response sensitivity. It analyzed the effect of integration time step on the accuracy and efficiency of these two formats, which provides a reference standard for selecting the sensitivity analysis of stochastic response.Secondly, the present study adopted time domain method of stochastic response sensitivity and moving asymptotes method of global convergence, investigating truss optimization problem constrained by non-stationary stochastic seismic downward movement. It tested the feasibility and practicability of this method through numerical example and analyzed the results after optimization. The results show that this method not only reduced structure vibration, but also saved the materials used in the structure, reflecting the value of engineering applications.Next, on the difference of time domain method and time domain explicit method, the present study adopted more practical and more efficient time-domain explicit method based on the impulse response function to solve stochastic response sensitivity, and applied the method to optimization problems under the constraint of both displacement and stress of truss structure. It tested the feasibility and practicability of this method through numerical example and analyzed the calculating efficiency and optimization effect. Eventually, this method is also applied to the optimization of space truss structure.Finally, a summary of the present study was made, and future research directions are discussed. |
