共查询到20条相似文献,搜索用时 676 毫秒
1.
王怀忠 《应用数学和力学(英文版)》1995,16(11):1039-1045
ELEMENT-BY-ELEMENTMATRIXDECOMPOSITIONANDSTEP-BY-STEPINTEGRATIONMETHODFORTRANSIENTDYNAMICPROBLEMSWangHuaizhong(王怀忠)(ReceivedJu... 相似文献
2.
侯赣生 《应用数学和力学(英文版)》1994,15(11):1035-1045
THEBOUNDEDEXTERMINATIONANDSTABILITYOFMUTUALINTERFERENCESYSTEMOFFOUR-DIMENSIONALSPECIESHouGan-sheng(侯赣生)(Depl.ofPhysics,Jiangx... 相似文献
3.
TWO-DIMENSIONALDEFORMATIONOFANANISOTROPICELASTICBODYWITHAPARABOLICBOUNDARYHuYuan-tai(胡元太)ZhaoXing-hua(赵兴华)(ShanghaiUniversity... 相似文献
4.
刘汉池 《应用数学和力学(英文版)》1995,(8)
STRESS-STBAINFIELDNEARCRACKTIPANDCALCULATIONOFCRITICALSTRESSOFCRACKPROPAGATIONINAPUREBENDINGBEAMOFRECTANGULARSECTIONWITHONE-S... 相似文献
5.
杨作东 《应用数学和力学(英文版)》1996,17(5):465-476
EXISTENCEOFPOSITIVESOLUTIONSFORACLASSOFSINGULARTWOPOINTBOUNDARYVALUEPROBLEMSOFSECONDORDERNONLINEAREQUATION(杨作东)EXISTENCEOFPOS... 相似文献
6.
ONTHEEXISTENCEANDSTABILITYOFSOLUTIONFORSEMI-HOMOGENEOUSBOUNDARYVALUEPROBLEMDongQinxi(董勤喜);HuangXiankai(黄先开)(ReceivedJuly.4.19... 相似文献
7.
APPROXIMATION THEORY OF THREE DIMENSIONAL ELASTIC PLATES AND ITS BOUNDARY CONDITIONS WITHOUT USING KIRCHHOFF-LOVE ASSUMPTIONS 总被引:2,自引:2,他引:0
钱伟长 《应用数学和力学(英文版)》1995,16(3):203-224
APPROXIMATIONTHEORYOFTHREEDIMENSIONALELASTICPLATESANDITSBOUNDARYCONDITIONSWITHOUTUSINGKIRCHHOFF-LOVEASSUMPTIONSChienWei-zang(... 相似文献
8.
THERMOELASTICITY ANALYSIS OF FINITE COMPOSITE LAMINATES WEAKENED BY MULTIPLE ELLIPTICAL HOLES 总被引:1,自引:0,他引:1
THERMOELASTICITYANALYSISOFFINITECOMPOSITELAMINATESWEAKENEDBYMULTIPLEELLIPTICALHOLESXuXi-wu(许希武)SunLiang-xin(孙良新)FanXu-qi(范绪箕)... 相似文献
9.
THREEDIMENSIONALSTRESSANALYSISOFSYMMETRICCOMPOSITELAMINATESUNDERUNIAXIALEXTENSIONANDIN-PLANEPURESHEARChicnwei-zang(钱伟长),Huang... 相似文献
10.
EQUILIBRIUMINABSTRACTECONOMICSWITHANON-COMPACTINFINITEDIMENSIONALSTRATEGYSPACEDingXie-ping(丁协平)(SichuanNorrnalUniversity,Chen... 相似文献
11.
Yang Qingsheng 《Acta Mechanica Sinica》1998,14(2):171-178
The paper describes use of self-consistent finite element method (SCFEM) for predicting effective properties of fiber composite
with partially debonded interface. The effective longitudinal Young's modulus and shear modulus for unidirectional fiber reinforced
composites with fiber-end cracks are calculated. Numerical results show that the effective properties are considerably influenced
by the fiber-end cracks. The effects of microstructural parameters, such as fiber volume fraction, modulus ratio of the constituents
and fiber aspect, on the effective properties of the composites were discussed.
The project supported by the National Natural Science Foundation of China 相似文献
12.
微结构对金属基复合材料宏观弹塑性性能的影响 总被引:1,自引:0,他引:1
采用广义自洽有限元迭代平均化方法分析SiC晶须增强铝基复合材料的弹塑性拉伸行为,研究纤维长径与体分比的变化对复合材料宏观弹塑性变形的影响。通过细观应力场的分析,讨论基体内塑性区的发展与复合材料宏观弹塑性变形过程之间的联系,指出纤维端头处基体塑性区的发展将对复合材料拉伸弹塑性行为有着显著影响。最后,还讨论了以名义屈服应力σ0.2来表征金属基复合材料的弹塑性特征的不足之处。 相似文献
13.
Chen Haoran Su Xiaofeng Tang Limin 《Acta Mechanica Solida Sinica》1996,9(1):52-58
The generalized self-consistent finite-element iterative averaging method was adopted toanalyze the elasto-plastic tensile properties of SiC whiskers reinforced aluminum matrix composites.The effects of varying fiber's aspect ratio and volume fraction on the macroscopic elasto-plastic defor-mation of the composites were studied.By the analysis of microscopic stress fields,the relation be-tween the propagation of the elasto-plastic region in the matrix and the macroscopic elasto-plastic de-formation of composites was discussed.It was found that the propagation of the plastic region in thematrix between the fiber's ends would affect prominently the elasto-plastic tensile behaviour of thecomposites.It was shown that the characterization of the stress-strain response in terms of the 0.2%offset yield strength is incomplete. 相似文献
14.
Song-lin Xu Z. P. Tang Jian-long Xu Xiang-yu Dai Yang-bo Guo 《Theoretical and Applied Fracture Mechanics》2004,41(1-3):301
Lots of work had been reported in the experimental investigation and modeling of the debonding and pullout behavior for straight crack-bridging fibers in brittle matrix composites, but few of them involving in the dynamic and/or non-straight fiber case. In this paper, a dynamic meso-scale model for non-straight fiber was proposed on the work of Chanvillard. The model was time-dependent and related to the impact loading through the interfacial shearing stress along the embedded part of the steel fiber, and properly setting the thresholds, the dynamic meso-damage model of the fiber's debonding and pullout process was eventually constructed. The model prediction fitted the experimental data of Chanvillard for non-straight steel fiber under static condition quite well and could demonstrate the rate sensitivity of the reinforcing effects of fibers. Then, a 3-D discrete meso-element method (DEM3) was used to simulate the dynamic pullout behavior of such fiber configurations as wiredrawn fibers from cementitious matrix with pores. Comparing to afro-mentioned model, DEM3 was more effective in simulating the complete procedures of matrix dynamic failure and fiber pullout and would be more helpful in the analyses of complicated configurations of fiber. 相似文献
15.
16.
The stress-concentration effect of fiber-end geometries on the propagating stress waves in composite models was investigated by the dynamic photoelastic method. Aluminum fibers with rectangular, semicircular, v- and wedgeshape ends simulating such materials as reinforced concrete and fiber-bundle-reinforced composites were cast in epoxy resin to form the models. Impact was applied by the bullet of a rilfe. The effects of the reinforced rod or fiber-bundle ends on the dynamic birefringent patterns were analyzed by comparing the fringe patterns at the same locations in a plain model of identical contour under the same loading conditions. 相似文献
17.
《International Journal of Solids and Structures》2003,40(7):1633-1651
A new model for a smart beam with a partially debonded active constrained layer damping (ACLD) patch is presented, and the effects of the debonding of the ACLD patch on both passive and hybrid control are investigated. In this model, both shear and compressional vibrations of the viscoelastic material (VEM) layer are considered. The moment inertia and the transverse shear effect are also taken into account based on the Timoshenko’s beam theory. The adhesive layer between the host beam and the piezoelectric sensor patch is modeled as an elastic load transferring media. The debonding of the ACLD patch is approximated by removing the VEM between the constraining layer and the host beam in the debonding region, and the continuity conditions are imposed based on displacement continuity and force balance. A modal velocity observer-based modal control scheme is also given to perform the active modal control of the beam. In order to examine the effects of part debonding of the ACLD patch, the characteristic equation of the beam treated with an ACLD patch is derived. The simulation example results show that an edge debonding of the ACLD patch can significantly affect both passive and hybrid control. It is also found that the additional mode induced by the debonding has unique effects on the modal damping ratios and frequencies of both open-loop and closed-loop system. 相似文献
18.
基于Li Fa Ming的平行棒模型,对短钢纤维增强砂浆的平板试件,在直接拉伸条件下的破坏行为进行了分析,假设试件由N根相互平行的复合棒组成,每根复合棒又由一根纤维棒和S根砂浆棒组成,考虑纤维在基体中分布的方向因子和长度因子.砂浆的损伤可按连续损伤力学进行处理,将Loland模型和Mazars模型加以改进来描述.依据多根纤维的拉拨模型,假定纤维与基体间界面的损伤由纤维脱粘长度与纤维插入长度的比值来描述,复合材料的损伤包括基体的损伤和纤维的损伤,借助已有的试验数据和文献资料来确定本构模型中的各种参数,成功建立了短钢纤维增强砂浆直接拉伸应力一应变全曲线模型.所建模型与试件在直接拉伸试验下的应力-应变全曲线进行了对比,结果较为吻合. 相似文献
19.
Experimental Analysis of Prepreg Tack 总被引:1,自引:0,他引:1
A probe tack test apparatus is designed to characterize the tack of carbon-epoxy prepreg. Tests are performed on both pure
resin and prepreg. The maximum debonding force seems to be a relevant measure of tack. First, results show that the response
of pure resin is similar to that of viscous silicon oil. Second, the shape of the response curve obtained for prepreg beyond
the maximum value of the debonding force is mainly due to structural effects. Third, the influence of contact force, contact
time, debonding rate, probe temperature and ageing conditions on the prepreg tack is investigated in relation with physical
phenomena involved in the debonding phase. 相似文献
20.
Failure in micro-reinforced composites is investigated numerically using the strain-gradient plasticity theory of Gudmundson [Gudmundson, P., 2004. A unified treatment of strain gradient plasticity. Journal of the Mechanics and Physics of Solids 52 (6) 1379–1406] in a plane strain visco-plastic formulation. Bi-axially loaded unit cells are used and failure is modeled using a cohesive zone at the reinforcement interface. During debonding a sudden stress drop in the overall average stress–strain response is observed. Adaptive higher-order boundary conditions are imposed at the reinforcement interface for realistically modeling the restrictions on moving dislocations as debonding occurs. It is found that the influence of the imposed higher-order boundary conditions at the interface is minor. If strain-gradient effects are accounted for a void with a smooth shape develops at the reinforcement interface while a smaller void having a sharp tip nucleates if strain-gradient effects are excluded. Using orthogonalization of the plastic strain gradient with three corresponding material length scales it is found that, the first length scale dominates the evaluated overall average stress–strain response, the second one only has a small effect and the third one has an intermediate effect. Finally, studies of reinforcement having elliptical cross-sections show rather significant gradients of stress which is not seen for the corresponding circular cross-sections. Also, an increased drop in the overall load carrying capacity is observed for cross-sections elongated perpendicular to the principal tensile direction compared to the corresponding circular cross-sections. 相似文献