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圆管及内充压力介质管道撞击损伤与破坏的研究进展 总被引:4,自引:0,他引:4
综述了国内外关于内空圆管及充有压力介质的管道经受局部撞击作用时的大变形与破坏的研究现状,从圆管的侧向撞击凹陷及其对管柱承载能力的影响、管壁的撞击穿透、圆管的斜冲击、内充介质及压力对冲击穿透的影响、分析模型等6个方面介绍了一些重要实验结果和处理该类问题的分析方法与力学模型,讨论并提供了一些在工程应用中有重要指导意义的研究结果.由于内充压力介质管道的冲击穿透破坏涉及内充压力介质与管壁在撞击过程中的相互耦合作用,其变形及破坏机理十分复杂,影响因素除了圆管的几何尺寸、支承形式、材料力学特性、弹体形状及冲击速度等,还包括内充介质密度及内充压力大小等诸多方面.本文对这一问题作了详细评述及讨论,指出了目前的研究结果中的不同结论,同时给出了内充压力介质对临界冲击穿透能量的影响趋势的最新研究结果,最后提出了进一步的研究方向以及采用的相应对策.图2参64 相似文献
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针对第六届全国大学生结构设计竞赛命题要求设计一个四层缩尺竹质吊脚楼框架,测试其在侧向冲击载荷作用下的加速度响应. 采用有限元软件LS-DYNA,对模型进行模拟分析. 结果表明,有限元计算与加载测试所得的加速度时程曲线吻合较好. 以该模型为基础进行参数分析,结果表明随拉带初始松弛量增大、撞击板质量减小,结构加速度响应增大;相较入射球质量,入射球速度对结构峰值加速度的影响更敏感,随入射球速度增大,结构峰值加速度增大. 相似文献
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Zhang Shanyuan Lei Jianping Zhao Longmao Cheng Guoqiang Lu Guoyun 《Acta Mechanica Solida Sinica》2000,13(2):166-172
This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully
filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The whole process of dynamic buckling
is simulated using LS-DYNA computer code. The consistency between experimental observation and numerical simulation is quite
satisfactory. The investigation indicates that quite high internal hydrodynamic pressure occurs inside the shell during the
impact process. Under the combined action of the high internal pressure and axial compression plastic buckling occurs easily
in the thin-walled shells and buckling modes take on regular and axisymmetric wrinkles.
This project is supported by the National Natural Science Foundation of China(19672039) and the Shanxi Foundation for Returned
Scholars from Abroad. 相似文献
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方管在高速撞击下的能量吸收能力 总被引:1,自引:0,他引:1
本文报导了速度约为100m/sec的子弹高速撞击铝合金方管的实验,表明在这种撞击条件下仍与准静态实验中一样,方管仍呈现“开裂与卷曲”的变形破坏模式,并证实了在高速碰撞下方管仍是一种极好的能量吸收装置.理论分析表明,在这种撞击条件下惯性力仍是不重要的;计入了应变率效应之后,理论预计的方管承载能力与实验符合良好. 相似文献
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Kil-Sung Lee Yong-Jun Yang Sun-Kyu Kim In-Young Yang 《Acta Mechanica Solida Sinica》2008,21(4):383-388
An experimental investigation was carried out to study the energy absorption characteristics of thin-walled square tubes subjected to dynamic crushing by impact loading to develop the optimum structural members. Here, the controller is introduced to improve and control the absorbed energy of thin-walled square tubes in this paper. When the controller were used, the experimental results of crushing of square tubes controlled by the controller's elements showed a good candidate for a controllable energy absorption capability in impact crushing. 相似文献
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正常牙齿存在许多薄弱结构,如窝沟、楔状缺损和牙隐裂等.如何评估这些薄弱结构对牙齿裂纹产生和断裂的影响,一直缺乏有效的评价方法.利用实验和有限元分析两种方法,初步分析了牙冠在静动载荷作用下的断裂模式.研究结果表明,结构因素是决定牙冠断裂的最重要因素,牙冠断裂常常发生在结构薄弱的地方,且牙冠断裂符合第二强度准则.本研究为临床诊断和治疗提供一定的理论依据. 相似文献
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RUPTURE OF THIN METAL TUBES BY NORMAL AND OBLIQUE IMPACT OF BLUNT CONICALNOSED MISSILES: EXPERIMENTS 总被引:1,自引:0,他引:1
Impact tests at both normal and oblique angles of incidence were conducted on thin mild tubes using a moderate size of 90°
conical-nosed missiles. The minimum impact speed that generated cracks through the thickness of the wall, termed the speed
for rupture, was measured, and various modes of rupture were identified. For a thin tube hit by a missile at a normal angle
of obliquity at the speed for rupture, the contact region spreads across the nose of the missile, and the transverse shear
deformation is predominant in the final failure process. If the angle of obliquity is 30°, the missile pierces a hole through
the wall of the tube. At the speed for rupture, the kinetic energy of the missile for oblique angle 30° is only about 45%
that required for plugging at a normal angle of obliquity.
The project sponsored by National Natural Science Foundation of China(No. 19842001, 19872048) and Scientific Research Foundation
for Returned Overseas Chinese Scholars of State Education Commission and Shanxi Province of China. 相似文献
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薄壁金属圆管在钝圆锥头弹体正冲击及斜冲击下破裂的实验研究 总被引:5,自引:0,他引:5
对薄壁软钢圆管在90°圆锥头子弹正冲击和斜冲击下的破裂进行了实验研究.测量了子弹以不同冲击角冲击时,圆管产生穿透性破裂的最小速度(临界破裂速度),找出管壁在不同冲击角下局部破裂的模式.在子弹以临界破裂速度正冲击下,靶壁逐渐覆盖整个弹头,管壁的最后破裂是剪切型的;当斜冲击角为30°时,子弹的尖端会刺透靶壁,在这些斜冲击角下,子弹的临界破裂动能仅仅是正冲击下的45%. 相似文献
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本文利用AMT铝合金三种不同厚度的圆柱壳,在常外压和不同轴向冲击载荷作用下的柱壳塑性动力屈曲问题。实验发现除了通常文献中提到的临界速度Vc1外,还有一个使柱壳发生较大变形而破坏时所对应的一个临界遵度Vc2。文章重点研究Vc2与轴向变形。柱壳厚度等之间关系以及柱壳屈曲形式。 相似文献
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This study discusses the experimental result of the viscoplastic response and col- lapse of sharp-notched 316L stainless steel tubes with different notched depths subjected to cyclic bending. The tube bending machine and curvature-ovalization measurement apparatus were used for conducting the symmetric curvature-controlled cyclic bending. To highlight the viscoplastic behavior, three different curvature-rates, 0.0035, 0.035 and 0.35 m-1s-1, were controlled. Ob- servations of a certain curvature-rate reveal that five almost parallel lines corresponding to five different notch-depth (0.2, 0.4, 0.6, 0.8 and 1.0 mm) tubes were presented in the experimental relationship between the cyclic controlled curvature and the number of cycles needed to pro- duce buckling on a log-log scale. However, the slopes for the three different curvature-rates are different. An empirical formulation was proposed to simulate the aforementioned relationship. When comparing with the experimental findings, the simulation was in good agreement with the experimental data. 相似文献
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利用自行研制的旋转盘式间接杆杆型冲击拉伸试验装置对ARALL材料以及施加预应力的ARALL材料进行了3个应变率(200、500、1300s-1)的冲击拉伸试验,得到了两种材料在不同应变率下的完整的应力应变曲线。结果表明ARALL材料在高速加载条件下的变形可以分为弹性变形、塑性变形和材料失稳后的残余变形三个部分,每个部分都有不同的变形机理。结果还表明,随着应变率的增加两种材料的屈服应力、失稳应力以及失稳应变均相应增加,表现出明显的应变率强化和动态韧性现象。最后根据材料在不同应变率下的试验结果,建立了ARALL材料计及应变率影响的三段线性本构模型。 相似文献