施工階段的結構物經常需要了解各個階段結構物的反應,利用傳統的數值方法模擬時經常會因各個階段分析模型的改變而需要增減元素或改變邊界條件,此時將造成分析模擬的困難,因此對於施工階段結構物的模擬,一般的作法是在每個階段都重新建立分析模型,但此種方式需要建立多個分析模型,將造成分析模擬的不便,爲改善此問題本研究嘗試利用向量式有限元素法模擬施工階段結構物的反應。 向量式有限元素法模擬問題時由於各質點的運動方程式及桿件內力計算獨立,並且不需建立整體勁度矩陣及迭代運算,使得模擬時可以方便的在不同階段進行分析模型元素的增減或邊界條件的改變,並且不需對原有的分析程式做太多的改變,因此可有效的模擬施工階段結構物受自重或其他外因影響的反應。本研究將簡單說明影響施工過程的變因,再將施工階段的概念導入向量式有限元素法,並以二維剛架元分析程式為基礎,進行元素增減及邊界條件改變的流程撰寫,同時做程式的基本驗證,再嘗試進行一些施工過程的模擬。
It is generally necessary to realize the behaviors at erection stages during construction. It is inconvenient to simulate the response of structures at erection stages while utilizing traditional numerical methods, which has to rebuild the analysis models at each erection stages involving increase and/or decrease elements and the change of boundary conditions. For improving this question, the vector form intrinsic finite element (VFIFE) method is used to simulate the behaviors of erection stages of structures at erection stages during construction. In VFIFE, the calculation is to solve a set of decoupled vector form equations, and the internal forces in the elements can be computed form the mass displacement, thus it is not needed assemble global stiffness matrices and iterations are not available. Hence, it is convenient to increase and/or decrease elements and the change of boundary conditions at erection stages during construction and can effectively simulate the responses subjected dead load and other influences. In this study, the erection procedures based on plane frame element was coded and verified, and some simulations of erection were investigated.