Dynamic fracture processes of L-shaped beam-column specimens with prefabricated cracks
-
摘要: 针对含预制裂纹L形梁柱试件，为研究预制裂纹动态扩展的力学特征及其对梁柱试件破坏模式的影响，采用数字动态焦散线实验系统，对距节点核心区不同距离l处含有预制裂纹的试件进行落锤冲击实验，得到预制裂纹的扩展轨迹、速度、动态应力强度因子的变化规律。结果表明，l值增大，扩展裂纹在梁下边缘的贯通点与预制裂纹的夹角逐渐增大，曲裂程度变大。裂纹扩展速度随着l的增大振荡性增强，裂纹扩展平均速度逐渐降低。l值为2 mm时，裂尖表现为Ⅰ型断裂，l值增大，裂尖受到剪应力作用增强，Ⅰ型动态应力强度因子减小，Ⅱ型动态应力强度因子增大，断裂逐渐转变为Ⅰ-Ⅱ复合型。Abstract: The dynamic propagation mechanics of prefabricated crack and its effect on joint were studied for the impact fracture process of L-shaped beam-column specimens with prefabricated cracks. The drop testing was carried out on the specimens with cracks at different distances l far from node core area by using the digital dynamic caustic system and the variations of crack propagation trajectory, velocity and dynamic stress-intensity factor were obtained. The results show that the increase of l leads to the angle between the penetration point of the extended crack at the edge of the beam and the prefabricated crack increases gradually and the degree of crack curving becomes larger. With the increase of l, the oscillation of crack propagation velocity increases, the average velocity decreases and the crack propagation time is gradually prolonged. When the value of l is 2 mm, the fracture pattern is mode Ⅰ. As the value of l increases, the crack tip is increased by the shear stress, the dynamic stress intensity factor of mode Ⅰ decreases and the dynamic stress intensity factor of mode Ⅱ gradually increases. The fracture pattern gradually becomes Ⅰ-Ⅱ complex mode.
-
Key words:
- beam-column specimen /
- impact /
- caustic /
- dynamic fracture /
- prefabricated crack /
- stress intensity factor
-
图 2 Ⅰ型和Ⅰ-Ⅱ复合型裂纹尖端焦散斑形状
Figure 2. Caustic shapes at crack tip under mode Ⅰand mixed mode
图 8 裂纹扩展水平位移和竖向位移时程曲线
Figure 8. Horizontal and vertical displacements ofcrack propagation varying with time
图 9 裂纹扩展方向与竖直方向夹角的时程曲线
Figure 9. Angle between crack propagation direction and vertical direction varying with time
图 13 动态应力强度因子时程曲线
Figure 13. The curves of dynamic intensity stress factor versus time
-
[1] 郑云, 叶列平, 岳清瑞.CFRP板加固含裂纹受拉钢板的疲劳性能研究[J].工程力学, 2007, 24(6):91-97. http://industry.wanfangdata.com.cn/dl/Detail/Periodical?id=Periodical_gclx200706016ZHENG Yun, YE Lieping, YUE Qingrui. Study on fatigue behavior of cracked tensile steel plates reinforced with CFRP plates[J]. Engineering Mechanics, 2007, 24(6):91-97. http://industry.wanfangdata.com.cn/dl/Detail/Periodical?id=Periodical_gclx200706016 [2] 范国玺, 宋玉谱, 王立成.钢筋混凝土框架结构梁柱中节点动态力学性能试验研究[J].振动与冲击, 2015, 34(12):58-64. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zdycj201512011FAN Guoxi, SONG Yupu, WANG Licheng. Experimental study on dynamic mechanical properties of interior RC frame beam-column joints[J]. Journal of Vibration and Shock, 2015, 34(12):58-64. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zdycj201512011 [3] 王元清, 周晖, 石永久, 等.基于裂纹扩展阻力曲线的钢结构构件断裂行为评估模型[J].清华大学学报(自然科学版), 2013, 53(5), 595-600. http://mall.cnki.net/magazine/Article/QHXB201305002.htmWANG Yuanqing, ZHOU Hui, SHI Yongjiu, et al. Fracture behavior evaluation model for steel structural components based on crack extension resistance curves[J]. Journal of Tsinghua University (Science & Technology), 2013, 53(5):595-600. http://mall.cnki.net/magazine/Article/QHXB201305002.htm [4] 王志华, 赵勇刚, 马宏伟.梁结构中裂纹参数识别方法研究[J].计算力学学报, 2006, 23(3):307-312. https://www.wenkuxiazai.com/doc/4e69730502020740be1e9b4a.htmlWANG Zhihua, ZHAO Yonggang, MA Hongwei. Investigation on crack identification in the beam-type structures[J]. Chinese Journal of Computational Mechanics, 2006, 23(3):307-312. https://www.wenkuxiazai.com/doc/4e69730502020740be1e9b4a.html [5] 周晖, 王元清, 石永久, 等.基于微观机理的梁柱节点焊接细节断裂分析[J].工程力学, 2015, 32(5):37-50. http://or.nsfc.gov.cn/bitstream/00001903-5/296412/1/1000014168465.pdfZHOU Hui, WANG Yuanqing, SHI Yongjiu, et al. Fracture analysis of welded details in beam-to-column connections using macromechanics-based models[J]. Engineering Mechanics, 2015, 32(5):37-50. http://or.nsfc.gov.cn/bitstream/00001903-5/296412/1/1000014168465.pdf [6] RUAN H H, YU T X. Deformation mechanism and defect sensitivity of notched free-free beam and cantilever beam under impact[J]. International Journal of Impact Engineering, 2003, 28(1):33-63. doi: 10.1016/S0734-743X(02)00024-6 [7] LIU J, ZHU W D, CHARALAMBIDES P G, et al. A dynamic model of a cantilever beam with a closed, embedded horizontal crack including local flexibilities at crack tips[J]. Journal of Sound and Vibration, 2016, 382:274-290. doi: 10.1016/j.jsv.2016.04.036 [8] MANOGG P. International conference on the physics of non-crystalline solids[M]. Netherlands, 1964:481-490. [9] THEOCARIS P S, PAPADOUPOUS G A. The influence of geometry of edge-cracked plates on KⅠ and KⅡ components of the stress intensity factor studied by caustics[J]. Journal of Physics D:Applied Physics, 1984, 17(12):2339-2349. doi: 10.1088/0022-3727/17/12/003 [10] YAO X F, JIN G C, ARAKAWA K, et al. Experimental studies on dynamic fracture behavior of thin plates with parallel single edge cracks[J]. Polymer Testing, 2002, 21(8):933-940. doi: 10.1016/S0142-9418(02)00037-5 [11] YANG R S, XU P, YUE Z W, et al. Dynamic fracture analysis of crack-defect interaction for mode I running crack using digital dynamic caustic method[J]. Engineering Fracture Mechanics, 2016, 161:63-75. doi: 10.1016/j.engfracmech.2016.04.042 [12] 李清, 刘绍兴, 苏鹏, 等.预制裂纹梁柱节点冲击破坏过程的动态焦散线实验研究[J].振动与冲击, 2008, 27(10):23-26. doi: 10.3969/j.issn.1000-3835.2008.10.006LI Qing, LIU Shaoxing, SU Peng, et al. Experimental study on impactive fracture behavior of a beam-column connection with cracks by caustic method[J]. Journal of Vibration and Shock, 2008, 27(10):23-26. doi: 10.3969/j.issn.1000-3835.2008.10.006 [13] 王综秩, 王元清, 杜新喜, 等.有机玻璃与不锈钢连接节点承载性能试验研究[J].东南大学学报(自然科学版), 2016, 46(1):105-109. doi: 10.3969/j.issn.1001-0505.2016.01.018WANG Zongzhi, WANG Yuanqing, DU Xinxi, et al. Experimental research on bearing capacity of joint of acrylic and stainless steel[J]. Journal of Southeast University (Natural Science Edition), 2016, 46(1):105-109. doi: 10.3969/j.issn.1001-0505.2016.01.018 [14] 黄川腾. 空心楼盖结构分析方法及板柱节点冲切问题研究[D]. 重庆: 重庆大学, 2015: 41-48. http://cdmd.cnki.com.cn/Article/CDMD-10611-1016704798.htm [15] 赵秋, 陈宝春, 郭智勇, 等.新月形拱-连续梁组合桥梁结构体系试验研究[J].土木工程学报, 2015, 48(增刊1):8-14. http://www.cnki.com.cn/Article/CJFDTotal-TMGC2015S1003.htmZHAO Qiu, CHEN Baochun, GUO Zhiyong, et al. Experimental studies on crescent arch-continuous beam composite bridge structures[J]. China Civil Engineering Journal, 2015, 48(suppl 1):8-14. http://www.cnki.com.cn/Article/CJFDTotal-TMGC2015S1003.htm [16] BEINERT J, KALTHOFF J F. Experimental determination of dynamic stress intensity factors by shadow patterns[M]. Netherlands:Springer, 1981:281-330. [17] KALTHOFF J F. Shadow optical method of caustics[M]//Handbook on Experimental Mechanics. New York:Prentice Hall, 1987:430-500. [18] TAKAHASHI K, ARAKAWA K. Dependence of crack acceleration on the dynamic stress-intensity factor in polymers[J]. Experimental Mechanics, 1987, 27(2):195-200. doi: 10.1007/BF02319474 [19] ZHANG Q B. A review of dynamic experimental techniques and mechanical behavior of rock materials[J]. Rock Mechanics and Rock Engineering, 2014, 47(4):1411-1478. doi: 10.1007/s00603-013-0463-y [20] BROKE D. Elementary engineering fracture mechanics[M]. Martinus Nijho Publishers, 1982:154-156. -
下载:
点击查看大图
图(14)
计量
- 文章访问数: 5326
- HTML全文浏览量: 1396
- PDF下载量: 192
- 被引次数: 0