NONLINEAR ANALYSIS OF TIMOSHENKO BEAM ELEMENT BASED ON IMPROVED COROTATIONAL FORMULATION
-
摘要: 为提高空间Timoshenko梁单元非线性问题的计算精度,在共旋坐标法的基础上,提出了一种改进的Timoshenko梁单元几何非线性分析方法。利用虚功原理得到改进空间梁单元的刚度矩阵;使用有限质点法中的逆向运动思路计算单元局部坐标系下的刚体旋转矩阵;根据整体坐标系与局部坐标系之间旋转角度的转化以及微分关系,求得空间梁单元的切线刚度矩阵;编制了相应的有限元程序,对多个经典的大变形结构进行几何非线性分析。计算结果印证了该文所提出改进方法的正确性,同时与传统共旋坐标法相比,具有更高的精度。
-
关键词:
- Timoshenko梁单元 /
- 共旋坐标法 /
- 逆向运动 /
- 非线性分析 /
- 切线刚度矩阵
Abstract: An improved geometrically nonlinear analysis method based on corotational formulation is proposed to improve the computation accuracy of nonlinear problems of spatial Timoshenko beam element. The stiffness matrix of the improved spatial beam element is obtained by using the principle of virtual work; The rigid-body rotation matrix of the element in local coordinate system is calculated by using the reverse motion approach in finite particle method; The tangent stiffness matrix of the spatial beam element is obtained according to the transformation and differential relationship of the rotation angle between the global coordinate system and the local coordinate system; A finite element program is made to analyze the geometric nonlinearity of several typical large deformation structures. The results show that the improved method proposed in this paper is correct and has higher accuracy than the traditional corotational formulation. -
表 1 悬臂梁承受集中荷载时的大挠度变形
Table 1. Cantilever's large deformation under concentrated load
$ P{L}^{2}/EI $ $ w/L $ $ u/L $ ${\theta }_{0}/{\rm rad}$ 解析解 本文 误差/(%) 解析解 本文 误差/(%) 解析解 本文 误差/(%) 0.2 0.0664 0.0665 0.1506 0.0027 0.0026 2.1852 0.0996 0.0996 0.0000 0.8 0.2495 0.2499 0.1603 0.0382 0.0381 0.2618 0.3791 0.3791 0.0000 1.6 0.4294 0.4305 0.2562 0.1186 0.1185 0.0843 0.6707 0.6711 0.0596 3.0 0.6033 0.6054 0.3481 0.2544 0.2544 0.0000 0.9860 0.9871 0.1116 4.0 0.6700 0.6728 0.4179 0.3289 0.3290 0.0304 1.1212 1.1227 0.1338 表 2 悬臂梁承受弯矩作用的大变形
Table 2. Cantilever’s large deformation under bending moment
$ k $ 水平位移
$ u $解析
解/m本文
解/mHAWC2-
30解/mHAWC2-
50解/m本文误
差/(%)HAWC2-
30误差/(%)HAWC2-
50误差/(%)竖直位移
$ v $解析
解/m本文
解/mHAWC2-
30解/mHAWC2-
50解/m本文误
差/(%)HAWC2-
30误差/(%)HAWC2-
50误差/(%)0.4 −2.4317 −2.4268 −2.4439 −2.4366 0.20 0.50 0.20 5.4987 5.5023 5.5042 5.4987 0.07 0.10 0.00 0.8 −7.6613 −7.6551 −7.7609 −7.6996 0.08 1.30 0.50 7.1978 7.2168 7.2194 7.2050 0.26 0.30 0.10 1.2 −11.5591 −11.5684 −11.6978 −11.6053 0.08 1.20 0.40 4.7986 4.8271 5.0145 4.8802 0.59 4.50 1.70 1.6 −11.8921 −11.9121 −12.0467 −11.9516 0.17 1.30 0.50 1.3747 1.3893 1.6868 1.5080 1.06 22.70 9.70 2.0 −10.0000 −10.0000 −10.5100 −10.2000 0.00 5.10 2.00 0.0000 0.0000 −0.0080 −0.0100 0.0000 −0.0080 −0.0100 表 3 自由端位移和转角参数比较
Table 3. Comparison of tip displacements and rotations
方法对比及误差分析 解析解/m 经典共旋法解/m HAWC2解/m 本文解/m 共旋法误差/(%) 本文误差/(%) HAWC2误差/(%) x方向位移 −0.090 64 −0.090 13 −0.091 64 −0.090 09 0.56 0.61 1.10 y方向位移 −0.064 84 −0.063 20 −0.067 24 −0.064 76 2.53 0.12 3.70 z方向位移 1.229 98 1.229 50 1.229 98 1.229 18 0.04 0.06 0.00 x方向扭转角度 0.184 45 0.184 47 0.188 88 0.184 40 0.01 0.03 2.40 y方向旋转角度 −0.179 85 −0.179 87 −0.179 87 −0.179 84 0.01 0.01 0.01 z方向旋转角度 0.004 88 0.005 23 0.004 99 0.005 01 7.17 2.66 2.30 表 4 自由端受力下曲梁端部位移比较
Table 4. Comparison of the curved beam tip displacements under a force applied at the free end
方法对比及
误差分析解析
解本文方
法解经典共
旋法解HAWC2
解本文
误差/(%)共旋法
误差/(%)HAWC2/
(%)$x/{\rm m}$ −23.7 −23.7 −23.8 −24.2 0.2 0.4 2.1 $y/{\rm m}$ −13.4 −13.6 −13.7 −13.8 1.3 2.2 3.1 ${\textit{z} }/{\rm m}$ 53.4 53.6 53.7 53.4 0.4 0.5 0.0 -
[1] 王涛, 刘德贵, 胡安杰. 基于流动坐标系的3维空间动力非线性有限元方法[J]. 振动与冲击, 2018, 324(16): 19 − 28, 42.WANG Tao, LIU Degui, HU Anjie. A nonlinear dynamic finite element in 3D space based on the Co-rotational formulation [J]. Journal of Vibration and Shock, 2018, 324(16): 19 − 28, 42. (in Chinese) [2] 邓继华. 基于共旋坐标法的结构非线性计算理论研究[D]. 长沙: 湖南大学, 2013.DENG Jihua. Study on non-linear calculation theory for structure based on co-rotational procedure [D]. Changsha: Hunan University, 2013. (in Chinese) [3] 史加贝, 刘铸永, 洪嘉振. 柔性多体动力学的共旋坐标法[J]. 力学季刊, 2017(2): 197 − 214.SHI Jiabei, LIU Zhuyong, HONG Jiazhen. The Co-rotational formulation for flexible multibody dynamics [J]. Chinese Quarterly of Mechanics, 2017(2): 197 − 214. (in Chinese) [4] WEMPNER G. Finite elements, finite rotations and small strains of flexible shells [J]. International Journal of Solids & Structures, 1969, 5(2): 117 − 153. [5] CRISFIELD M A. A consistent co-rotational formulation for non-linear three-dimensional beam-elements [J]. Computer Methods in Applied Mechanics & Engineering, 1990, 81(2): 131 − 150. [6] AREIAS P, GARO J, PIRES E B, et al. Exact corotational shell for finite strains and fracture [J]. Computational Mechanics, 2011, 48(4): 385 − 406. doi: 10.1007/s00466-011-0588-3 [7] STÄBLEIN, HANSEN A, HARTVIG M. Timoshenko beam element with anisotropic cross-sectional properties [C]// VII European Congress on Computational Methods in Applied Sciences and Engineering, 2016. [8] 邓继华, 谭建平, 谭平, 等. 基于共旋法与稳定函数的几何非线性平面梁单元[J]. 工程力学, 2020, 37(11): 37 − 44. doi: 10.6052/j.issn.1000-4750.2020.01.0012DENG Jihua, TAN Jianping, TAN Ping, et al. Tian Zhongchu. A geometric nonlinear plane beam element based on corotational formulation and on stability functions [J]. Engineering Mechanics, 2020, 37(11): 37 − 44. (in Chinese) doi: 10.6052/j.issn.1000-4750.2020.01.0012 [9] 杨浩文, 吴斌, 潘天林, 等. Timoshenko梁能量守恒逐步积分算法[J]. 工程力学, 2019, 36(6): 21 − 28. doi: 10.6052/j.issn.1000-4750.2018.01.0033YANG Haowen, WU Bin, PAN Tianlin, et al. Energy-conserving time integration method for Timoshenko beams [J]. Engineering Mechanics, 2019, 36(6): 21 − 28. (in Chinese) doi: 10.6052/j.issn.1000-4750.2018.01.0033 [10] 杜轲, 滕楠, 孙景江, 等. 基于共旋坐标和力插值纤维单元的RC框架结构连续倒塌构造方法[J]. 工程力学, 2019, 36(3): 95 − 104. doi: 10.6052/j.issn.1000-4750.2018.01.0055DU Ke, TENG Nan, SUN Jingjiang, et al. A progressive collapse analytical model of RC frame structures based on coretational formulation for force-based fiber elements [J]. Engineering Mechanics, 2019, 36(3): 95 − 104. (in Chinese) doi: 10.6052/j.issn.1000-4750.2018.01.0055 [11] KAN Z, DONG K, CHEN B, et al. The direct force correction based framework for general co-rotational analysis [J]. Computer Methods in Applied Mechanics and Engineering, 2021, 385: 114018. doi: 10.1016/j.cma.2021.114018 [12] NOUR-OMID B, RANKIN C C. Finite rotation analysis and consistent linearization using projectors [J]. Computer Methods in Applied Mechanics & Engineering, 1991, 93(3): 353 − 384. [13] LE T N, BATTINI J M, HJIAJ M. A consistent 3D corotational beam element for nonlinear dynamic analysis of flexible structures [J]. Computer Methods in Applied Mechanics & Engineering, 2014, 269: 538 − 565. [14] CRISFIELD M A, GALVANETTO U, JELENIC G. Dynamics of 3-D co-rotational beams [J]. Computational Mechanics, 1997, 20(6): 507 − 519. doi: 10.1007/s004660050271 [15] HSIAO K M. Corotational total Lagrangian formulation for three-dimensional beam element [J]. AIAA Journal, 1992, 30(3): 797 − 804. doi: 10.2514/3.10987 [16] 郭鑫, 李东升, 魏达, 等. 基于解析位移形函数的改进风力机叶片梁单元[J]. 太阳能学报, 2022, 43(4): 387 − 392. doi: 10.19912/j.0254-0096.tynxb.2020-0805GUO Xin, LI Dongsheng, WEI Da, et al. Improved beam element for wind turbine blades based on analytical displacement shape functions [J]. Acta Energiae Solaris Sinica, 2022, 43(4): 387 − 392. (in Chinese) doi: 10.19912/j.0254-0096.tynxb.2020-0805 [17] HODGES D H, ATILGAN A R, FULTON M V, et al. Free-Vibration Analysis of Composite Beams [J]. Journal of the American Helicopter Society, 1991, 36(3): 36 − 47. doi: 10.4050/JAHS.36.36 [18] GIAVOTTO V, BORRI M, MANTEGAZZA P, et al. Anisotropic beam theory and applications [J]. Computers & Structures, 1983, 16(1/2/3/4): 403 − 413. [19] BATTINI J M, PACOSTE C. Co-rotational beam elements with warping effects in instability problems [J]. Computer Methods in Applied Mechanics & Engineering, 2002, 191(17/18): 1755 − 1789. [20] 罗尧治, 郑延丰, 杨超, 等. 结构复杂行为分析的有限质点法研究综述[J]. 工程力学, 2014, 31(8): 1 − 7, 23. doi: 10.6052/j.issn.1000-4750.2013.05.ST14LUO Yaozhi, ZHENG Yanfeng, YANG Chao, et al. Review of the finite particle method for complex behaviors of structures [J]. Engineering Mechanics, 2014, 31(8): 1 − 7, 23. (in Chinese) doi: 10.6052/j.issn.1000-4750.2013.05.ST14 [21] 黄正, 刘石, 杨毅, 等. 基于非线性梁理论的有限质点法[J]. 计算力学学报, 2019, 36(5): 610 − 617. doi: 10.7511/jslx20180703001HUANG Zheng, LIU Shi, YANG Yi, et al. Finite particle method based on nonlinear beam theory [J]. Chinese Journal of Computational Mechanics, 2019, 36(5): 610 − 617. (in Chinese) doi: 10.7511/jslx20180703001 [22] 蔡松柏, 沈蒲生. 大转动平面梁有限元分析的共旋坐标法[J]. 工程力学, 2006, 23(增刊 1): 69 − 72.CAI Songbai, SHEN Pusheng. Co-rotational procedure for finite element analysis of plane beam under large rotational displacement [J]. Engineering Mechanics, 2006, 23(Suppl 1): 69 − 72. (in Chinese) [23] QI W, SPRAGUE M A, JONKMAN J M. Nonlinear legendre spectral finite elements for wind turbine blade dynamics [J]. AIAA Journal, 2014(6): 12 − 24. [24] CHOI M J, SAUER R A, KLINKEL S. An isogeometric finite element formulation for geometrically exact Timoshenko beams with extensible directors [J]. Computer Methods in Applied Mechanics and Engineering, 2021, 385: 113993. doi: 10.1016/j.cma.2021.113993 [25] WANG Q, SPRAGUE M A, JONKMAN J, et al. BeamDyn: A high‐fidelity wind turbine blade solver in the FAST modular framework [J]. Wind Energy, 2017, 20(8): 5 − 9. [26] BATHE K J, BOLOURCHI S. Large displacement analysis of three‐dimensional beam structures [J]. International Journal for Numerical Methods in Engineering, 2010, 14(7): 961 − 986. -