Talk about dynamic strength and damage evolution
-
摘要: 材料强度在传统上常理解为材料在外载荷下抵抗流动/变形和破断的能力。由流变阶段到貌似突发的破断，其实源于一个隐含的应变率/时间相关的损伤演化过程。动态损伤演化研究的难点在于损伤与流变总是耦合在一起发展的。研究发现，热激活损伤演化模型可成功描述材料宏观损伤的动态演化。在此基础上，从实测的含损伤演化的表观应力应变曲线，可将两者解耦分开，并可确定各自相关的材料参数。这一思路可推广到中医脉诊的客观化研究，通过脉搏波信息定量反演脉搏波系统的正常及病态本构关系，可诊断生命体偏离正常状态的程度(病情)，这可视为一种广义的损伤演化和强度问题。上述思路还可推广到地震预报研究，即“对地球把脉”。与加卸载响应比理论相结合，通过相邻3处的地震波信息来反演地球相关板块含损伤演化的非线性载荷-响应曲线，再区分出损伤演化程度，将有利于改进地震预报，这可视为另一种广义的损伤演化和强度问题。Abstract: The strength of a material is traditionally understood as its ability to resist flow/deformation and breakage (brittle fracture or ductile rupture) under applied load. The breakage, though looking like an abrupt occurrence, actually results from a strain-rate/time dependent process of damage evolution. The difficulty in studying dynamic damage evolution lies in that the damage evolution and the flow/deformation process are coupled and influence each other. It was found that the dynamic evolution of macro-damage could be successfully described by the thermo-activated damage evolution model. Based on this model, the damage evolution and the flow/deformation can be decoupled from the experimentally measured apparent stress-strain curve with damage evolution, and the related material parameters can be determined. Such an approach is then generalized to the objective study of the TCM pulse. The normal and pathological constitutive relations of the pulse wave system can be inversely determined by pulse wave signals, and then the degree of deviation from the normal condition (illness state) of patients can be diagnosed, and their illness state can be regarded as a kind of generalized damage. The same approach is further generalized to the study of earthquake prediction through the 'pulse-taking for the earth'. Combined with the load-unload response ratio theory, by measuring the seismic wave signals on three adjacent positions, the nonlinear constitutive load-response curve with damage evolution can be inversely determined for the tectonic plates of the earth concerned, then the degree of the damage can be finally discriminated, which is the key information for an improved earthquake prediction.
-
Key words:
- dynamic strength /
- damage evolution /
- dynamics of materials /
- pulse wave /
- earthquake prediction
-
图 2 PMMA不同应变率下的理论曲线与实验数据的对比
Figure 2. Comparisons between the experimental data and theoretical predictions for PMMA
图 3 PP/PA共混高聚物BP神经网络预示曲线与实验曲线对比
Figure 3. Comparisons between the BP neural networks predictions and experimental data for PP/PA polymer blend
图 4 PP/PA共混高聚物由BP神经网络确定的D=(ε, ${\mathit{\dot \varepsilon }}$)
Figure 4. The D=(ε, ${\mathit{\dot \varepsilon }}$) determined by the BP neural networks for PP/PA polymer blend
图 5 计及损伤演化的材料率-温相关的动态力学行为的示意图
Figure 5. Rate-temperature dependent behavior of materialstaking account of damage evolution
-
[1] 中国大百科全书总委员会.中国大百科全书:力学[M].北京:中国大百科全书出版社, 1985:397. [2] Timoshenko S P. Strength of materials[M]. New York: Van Nostrand Company, 1930. [3] Lindholm U S. Review of dynamic testing techniques and material behavior[C]//Proceedings of Conference on Mechanical Properties of Materials at High Rates of Strain. London: Institute of Physics, 1974: 3-21. [4] Kachanov L M. Time of the rupture process under creep conditions[J]. Izv AN SSSR Otd Tekhn Nauk, 1958, 8:26-31. [5] 王礼立.绝热剪切: 材料在冲击载荷下的本构失稳[M].王礼立, 余同希, 李永池.冲击动力学进展.合肥: 中国科学技术大学出版社, 1992: 3-33. [6] 王礼立, 蒋昭镳, 陈江瑛.材料微损伤在高速变形过程中的演化及其对率型本构关系的影响[J].宁波大学学报(理工版), 1996, 9(3):47-55. Wang Lili, Jiang Zhaobiao, Chen Jiangying. Micro-damage evolution in high velocity deformation and its influence on rate-dependent constitutive relation of materials[J]. Journal of Ningbo University (Natural Science & Engineering Edition), 1996, 9(3):47-55. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199600379176 [7] Wang Lili, Jiang Zhaobiao, Chen Jiangying. Studies on rheological relation of materials by taking account of rate-dependent evolution of internal defects at high strain rates[M]//Wang Ren. Rheology of Bodies with Defects. Dordrecht: Kluwer Academic Publishers, 1999: 167-178. [8] Huang Dejin, Shi Shaoqiu, Wang Lili. Studies on rate-dependent evolution of damage and its effects on dynamic constitutive response by using a random fuse network model[M]//Chiba A, Tanimura S, Hokamoto K. Impact Engineering and Application. Tokyo: Elsevier Science Ltd., 2001: 743-748. [9] Wang Lili, Zhou Fenghua, Sun Zijian, et al. Studies on rate-dependent macro-damage evolution of materials at high strain rates[J]. International Journal of Damage Mechanics, 2010, 19(7):805-820. doi: 10.1177/1056789509359654 [10] Wang Lili, Hu Shisheng, Yang Liming, et al. Development of experimental methods for impact testing by combining Hopkinson pressure bar with other techniques[J]. Acta Mechanica Solida Sinica, 2014, 27(4):331-344. doi: 10.1016/S0894-9166(14)60041-0 [11] 王礼立, 胡时胜, 杨黎明, 等.材料动力学[M].合肥:中国科学技术大学出版社, 2016. [12] Curran D R, Shockey D A, Seaman L. Dynamic fracture criteria for a polycarbonate[J]. Journal of Applied Physics, 1973, 44(9):4025-4038. doi: 10.1063/1.1662891 [13] Seaman L, Curran D R, Shockey D A. Computational models for ductile and brittle fracture[J]. Journal of Applied Physics, 1976, 47(11):4814-4826. doi: 10.1063/1.322523 [14] Curran D R, Seaman L, Shockey D A. Dynamic failure of solid[J]. Physics Report, 1987, 147(5/6):253-388. http://d.old.wanfangdata.com.cn/Periodical/zjdxxb-e201310004 [15] Curran D R, Seaman L. Simplified models of fracture and fragmentation[C]//High-pressure Shock Compression of Solids Ⅱ: Dynamic Fracture and Fragmentation. New York: Springer-Verlag, 1996: 340-365. https://www.researchgate.net/publication/267469369_Simplified_Models_of_Fracture_and_Fragmentation [16] Zhurkov S N, Sanfirova T P. The temperature and time dependence of the strength of pure metals[J]. DoklAkadNauk SSSR, 1955, 101:237. [17] 周风华, 王礼立, 胡时胜.有机玻璃在高应变率下的损伤型非线性粘弹性本构关系及破坏准则[J].爆炸与冲击, 1992, 12(4):333-342. Zhou Fenghua, Wang Lili, Hu Shisheng. A damage-modified nonlinear visco-elastic constitutive relation and failure criterion of PMMA at high strain-rates[J]. Explosion and Shock Waves, 1992, 12(4):333-342. http://www.bzycj.cn/CN/abstract/abstract10751.shtml [18] Wang Lili, Xu Mingqiao, Shi Shaoqiu. Application of BP neural network to SHPB technique for the investigation of impact response of polymers[C]//Proceedings of 2003 SEM Annual Conference on Experimental and Applied Mechanics. Charlotte, North Carolina, USA, 2003: 167-174. [19] 王礼立, 赖华伟, 孙紫建, 等.高聚物计及损伤演化的动态变形和断裂[J].宁波大学学报(理工版), 2003, 16(6):372-380. Wang Lili, Lai Huawei, Sun Zijian, et al. Dynamic deformation and fracture of polymers taking account of damage evolution[J]. Journal of Ningbo University (Natural Science & Engineering Edition), 2003, 16(6):372-380. http://d.old.wanfangdata.com.cn/Periodical/nbdxxb-lg200304008 [20] Xu Mingqiao, Wang Lili. A new method for studying the dynamic response and damage evolution of polymers at high strain rates[J]. Mechanics of Materials, 2006, 38(1/2):68-75. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=96989ba269e795de8f28b4a6c39d1234 [21] Wang L, Xu M, Zhu J, et al. A method of combined SHPB technique and BP neural network to study impact response of materials[J]. Strain, 2006, 42(3):149-158. doi: 10.1111/str.2006.42.issue-3 [22] Sun Zijian, Wang Lili. Studies on impact constitutive behavior and dmage evolutionfor PP/PA polymer blends at large deformation[J]. Journal de Physique IV, 2006, 134:117-124. doi: 10.1051/jp4:2006134019 [23] Wang Lili, Wang Hui. Mechanics modeling and inverse analyses of pulse wave system from the view-point of traditional Chinese medicine[C]//Proceedings of ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. Busan, South Korea, 2016: OMAE2016-55106. http://en.cnki.com.cn/Article_en/CJFDTotal-LXXB201606017.htm [24] 王礼立, 王晖.脉搏波系统的力学模型及反演兼对若干中医学问题的讨论[J].力学学报, 2016, 48(6):1416-1424. Wang Lili, Wang Hui. Mechanical modeling and inverse analyses of pulsewaves system with discussions on some concepts in the traditional Chinese medicine[J]. Chinese Journal of Theoretical and Applied Mechanics, 2016, 48(6):1416-1424. http://d.old.wanfangdata.com.cn/Periodical/lxxb201606018 [25] Wang Lili. Foundations of stress waves[M]. Amsterdam: Elsevier, 2007. [26] 王琦.中医体质学[M].北京:人民卫生出版社, 2009. [27] 王琦.九种体质使用手册[M].长春:北方妇女儿童出版社, 2010. [28] 王晖.体质的中医保健[M].宁波:宁波出版社, 2009. [29] 王晖.全国名老中医王晖学术经验撷英[M].北京:中国中医药出版社, 2014. [30] 尹祥础.地震预测新途径的探索[J].中国地震, 1987, 3(1):1-7. Yin Xiangchu.The new approach of earchquake prediction[J]. Earthquake Research in China, 1987, 3(1):1-7. http://d.old.wanfangdata.com.cn/Periodical/kjcgglyyj201103032 [31] 尹祥础.加卸载响应比理论及其应用[M].北京:科学出版社, 2016." -
下载:
图(6)
计量
- 文章访问数: 8593
- HTML全文浏览量: 4227
- PDF下载量: 1061
- 被引次数: 0