摘要
为了提出一种不仅满足梁杆结构工程需要,而且涉及的物理量测量简便的动态屈曲准则,以轴向重物冲击下微弓形扁长金属杆的弹塑性动态屈曲为例,采用显式动力学有限元仿真分析方法,分析了不同重物冲击速度下扁长杆的动态响应,归纳了在轴向冲击作用下杆的弹塑性动态屈曲准则,应用此准则进一步研究了扁长杆的初始条件参数(材料屈服应力、预制弓形幅值和截面尺寸等)与临界冲击速度关系,验证了此准则的一般性和有效性。经过研究,提出了在轴向冲击作用下杆的动态屈曲准则——加载分离准则:重物对杆的轴向加载过程中,杆的加载端与重物发生明显的分离。加载分离准则可以满足工程需要,与基于载荷-响应曲线的B-R(Budiansky-Roth)运动准则相比,涉及的物理量测量更为简便。与提高扁长杆的材料强度和加工精度相比,增大截面尺寸是提高其动态屈曲强度的较有效方法。
Abstract
In order to propose an elastic-plastic dynamic buckling criterion for satisfying engineering requirements of beam and rod structures and simplifying measurement method, taking elastic-plastic dynamic buckling of a micro-bow flat long metal rod under axial weight impact as an example, dynamic responses of the rod under different axial impact velocities were analyzed with the explicit dynamic finite element simulation analysis method to generalize an elastic-plastic dynamic buckling criterion. Using this criterion, relations among initial condition parameters of the flat long rod including material yield stress, deflection and cross-section size of prefabricated micro-bow shape, etc. and critical impact velocity were further studied to verify the universality and effectiveness of the criterion. After investigation, the rod dynamic buckling criterion under action of axial impacts, i.e., the loading-separation criterion was proposed, it was described that if a rod is loaded by weights in axial direction, as soon as an obvious separation between its loaded end and weights happens, it enters dynamic buckling. It was shown that the loading-separation criterion can satisfy engineering requirements; compared with Budiansky-Roth (BR) motion criterion based on load-response curve, the measurements for physical variables involved to this criterion are easier and simpler; compared with enhancing material strength and improving machining accuracy of the flat long rod, increase in its cross-section size is more effective to lift its dynamic buckling strength.
关键词
动态屈曲准则 /
杆 /
轴向冲击 /
有限元分析 /
加载分离
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Key words
dynamic buckling criterion /
bar /
axial impact /
finite element analysis /
load-separation
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刘赛1,张伟贵2,肖凯1,苏玲1,王悦1.
轴向冲击作用下杆的弹塑性动态屈曲准则[J]. 振动与冲击, 2019, 38(19): 144-148
LIU Sai1,ZHANG Weigui2, XIAO Kai1,SU Ling1,WANG Yue1.
Elastic-plastic dynamic buckling criterion of rods under axial impact[J]. Journal of Vibration and Shock, 2019, 38(19): 144-148
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参考文献
[1] Lee L H N. Bifurcation and uniqueness in dynamics of elastic-plastic continua [J]. International Journal of Engineering Science,1975,13(1):69-76.
[2] Lee L H N. Quasi-bifurcation in dynamics of elastic-plastic continua [J]. Journal of Applied Mechanics,1977,44(3):413-418.
[3] 毛柳伟,王安稳,邓磊,等. 应力波作用下弹性直杆动力分叉屈曲研究[J]. 振动与冲击,2014,33(6):174-178.
Mao Liuwei,Wang Anwen,Deng Lei,et al. Dynamic bifurcation buckling of elastic rods under stress wave [J]. Journal of Vibration and Shock,2014,33(6):174-178.
[4] 陈得良,汪亚运,彭旭龙,等. 弹性压应力波下轴向功能梯度变截面梁动力压曲稳定分析[J]. 振动与冲击,2017,36(13):27-32.
Chen Deliang,Wang Yayun,Peng Xulong,et al. Dynamic buckling of axially functionally-graded beams with non-uniform cross-section under elastic compression stress wave [J]. Journal of Vibration and Shock,2017,36(13):27-32.
[5] Abrahams G R,Goodier J N. Dynamic flexural buckling of rods within an axial plastic compression wave [J]. Journal of Applied Mechanics,1966,33(2):241-247.
[6] 张清杰,李世其,郑际嘉. 轴向砰击杆的动力响应与屈曲[J]. 中国造船,1990(3):64-74.
Zhang Qingjie,Li Shiqi,Zheng Jijia. Dynamic response and buckling of axially-slammed columns [J]. Shipbuilding of China,1990(3):64-74.
[7] Zhang Z,Taheri F. Numerical studies on dynamic pulse buckling of FRP composite laminated beams subject to an axial impact [J]. Composite Structures,2002,56(3):269-277.
[8] Budiansky B,Roth R S. Axisymmetric dynamic buckling of clamped shallow spherical shells [R]. TN D-1510,USA:NASA,1962.
[9] Kardomateas G A,Simitses G J,Shen L,et al. Buckling of sandwich wide columns [J]. International Journal of Non-Linear Mechanics,2002,37(7):1239-1247.
[10] 陈国胜,唐文勇,张圣坤. 含脱层损伤复合材料层合梁的冲击动力屈曲[J]. 计算力学学报,2007,24(4):486-493.
Chen Guosheng,Tang Wenyong,Zhang Shengkun. Dynamic buckling of laminated composite beams with delamination subject to axial impact [J]. Chinese Journal of Computational Mechanics,2007,24(4):486-493.
[11] Hayashi T,Sano Y. Dynamic buckling of elastic bars (2nd report, the case of high velocity impact) [J]. Bulletin of the Japan Society of Mechanical Engineers,1972,15(88):1176-1184.
[12] 刘赛,吕振华. 扁长杆的冲击弹塑性屈曲特性分析的仿真有限元模型[J]. 清华大学学报(自然科学版),2016,56(10):1104-1108.
Liu Sai,Lv Zhenhua. Finite element model refinement for elastic-plastic dynamic buckling of a belt bar under impact [J]. Journal of Tsinghua University(Science and Technology),2016,56(10):1104-1108.
[13] Hayashi T,Sano Y. Dynamic buckling of elastic bars (1st report, the case of low velocity impact) [J]. Bulletin of the Japan Society of Mechanical Engineers,1972,15(88):1167-1175.
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脚注
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