- 摘 要
-
(1 清華大學(xué)土木工程系， 北京 100084； 2 華中科技大學(xué)土木工程與力學(xué)學(xué)院， 武漢 430074)
［摘要］強(qiáng)震作用下桁架結(jié)構(gòu)中的桿件破壞形式一般為受壓屈曲和受拉屈服，但是常用的雙線性理想模型不能考慮桿件受壓屈曲的情況。根據(jù)桿件受壓屈曲時(shí)的物理行為推導(dǎo)了相應(yīng)的顯式表達(dá)式，并嵌入到顯式動(dòng)力分析方法中實(shí)現(xiàn)了空間桁架結(jié)構(gòu)的地震倒塌分析。采用三種不同的桿單元模型，對一個(gè)三層空間桁架進(jìn)行了動(dòng)力彈塑性分析，并與ANSYS的計(jì)算結(jié)果進(jìn)行了對比，發(fā)現(xiàn)桿單元模型對結(jié)構(gòu)的響應(yīng)影響較大，壓桿屈曲軟化模型既能模擬桿件受拉屈服，又可以考慮桿件受壓非線性屈曲，能較合理地模擬結(jié)構(gòu)的動(dòng)力響應(yīng)。最后分別對三種單元模型定義了相應(yīng)的破壞準(zhǔn)則，比較了高聳輸電塔桁架結(jié)構(gòu)在不同破壞準(zhǔn)則下地震倒塌特征，該結(jié)構(gòu)在壓桿屈曲破壞準(zhǔn)則下發(fā)生倒塌時(shí)的最小加速度峰值PGA為11.7m/s2,具有較高的安全系數(shù)。
［關(guān)鍵詞］空間桁架結(jié)構(gòu)； 桿單元模型； 破壞準(zhǔn)則； 顯式動(dòng)力分析； 地震倒塌
中圖分類號：TU398-7文獻(xiàn)標(biāo)識碼：A文章編號：1002-848X(2020)23-0071-06
Seismic collapse simulations of space truss structures based on compression buckling member model
ZHENG Huadong1, FAN Jian2, ZHANG Yaoting2
(1 Department of Civil Engineering, Tsinghua University, Beijing 100084, China;2 College of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan 430074, China)
Abstract:The failure modes of truss structures subjected to strong earthquakes are buckling in compression or yielding in tension. However, the ideal bilinear model used in computaions fails to consider the nonlinear buckling behavior. Based on the physical behavior of the compression member under compression and buckling, an explicit expression was derived and embedded into the explicit dynamic analysis method to realize the seismic collapse analysis of the space truss structure. Three different truss member model were used to analyze the dynamic elasto-plasticity of a three-layer space truss, and the results were compared with those of ANSYS. It was found that the truss member model had a great influence on the response of the structure, and the developed compression member buckling and softening model could not only simulate the tensile yielding of the member, but also consider the nonlinear flexure of the member under compression, which could reasonably simulate the dynamic response of the structure. Finally, corresponding failure criteria were defined for each of the three unit models to compare the seismic collapse characteristics of the tower truss structure under different failure criteria. The PGA to the seismic collapse of this transmission tower under the buckling failure criterion is 11.7m/s2, which shows the structure is of high safety.
Keywords:space truss structure; truss member model; failure criterion; explicit dynamic analysis; seismic collapse
*國家自然科學(xué)基金資助項(xiàng)目(51078166, 51278218)。
通信作者：樊劍，博士，副教授，Email:fanjian@hust.edu.cn。
- 下載地址
-
