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91.
Java虚拟机中类装载机制的原理分析与应用研究 总被引:1,自引:0,他引:1
Java类的动态装载机制是Java虚拟机的一项核心技术,可以在运行时刻动态地加载或替换系统的某些功能模块,而不影响系统其它功能模块的正常运行。本文介绍了Java虚拟机中类的动态装载机制的原理、实现及应用,分析了类装载器的结构、用途,阐述了利用自定义类装载器装载并执行Java类的过程。 相似文献
92.
93.
A Review of Critical Plane Orientations in Multiaxial Fatigue Failure Criteria of Metallic Materials 总被引:1,自引:0,他引:1
The paper presents a review of multiaxial fatigue failure criteria based on the critical plane concept. The criteria have
been divided into three groups, according to the fatigue damage parameter used in the criterion, i.e. (i) stress, (ii) strain
and (iii) strain energy density criteria. Each criterion was described mainly by the critical plane orientation. Multiaxial
fatigue criteria based on the critical plane concept usually apply different loading parameters in the critical plane whose
orientation is determined by (a) only shear loading parameters (crack Mode II or III), (b) only normal loading parameters
(crack Mode I) or sometimes (c) mixed loading parameters (mixed crack Mode). There are also criteria based on few critical
plane orientations and criteria based on critical plane orientations determined by a weighted averaging process of rotating
principal stress axes. 相似文献
94.
The paper presents findings of the study of viscoplastic properties of several titanium alloys subjected to cyclic loading under complex stress state conditions. The applicability of elastic viscoplastic models to structural materials has been experimentally verified.__________Translated from Problemy Prochnosti, No. 3, pp. 37 – 44, May – June, 2005. 相似文献
95.
S. Garcia A. Amrouche G. Mesmacque X. Decoopman C. Rubio 《International Journal of Fatigue》2005,27(10-12):1347
Fatigue damage accumulation of cold expanded hole in aluminum alloys used in land transportation components was investigated. Tests were carried out using pre-cracked SENT specimens and inserting an expanded hole at the crack tip. The degree of the cold expansion was chosen equal to 4.3%. Tests were performed in two and four block loading under constant amplitude. Two sequences were compared.The increasing and the decreasing magnitude were compared. The experimental results were compared to the damage calculated by the Miner's rule and a new simple fatigue damage indicator. This comparison shows that the ‘model of the damage stress’, which take into account of the loading history, yields a good estimation of the experimental results. Moreover, the error is minimized in comparison to the Miner's model. 相似文献
96.
The fracture behavior of a composite/adhesive/steel bonded joint was investigated by using double cantilever beam specimens. A starter crack is embedded at the steel/adhesive interface by inserting Teflon tape. The composite adherend is a random carbon fiber reinforced vinyl ester resin composite while the other adherend is cold rolled steel. The adhesive is a one-part epoxy that is heat cured. The Fernlund-Spelt mixed mode loading fixture was employed to generate five different mode mixities. Due to the dissimilar adherends, crack turning into the adhesive (or crack kinking) associated with joint failure, was observed. The bulk fracture toughness of the adhesive was measured separately by using standard compact tension specimens. The strain energy release rates for kinking cracks at the critical loads were calculated by a commercial finite element analysis software ABAQUS in conjunction with the virtual crack closure technique. Two fracture criteria related to strain energy release rates were examined. These are (1) maximum energy release rate criterion (Gmax) and, (2) mode I facture criterion (GII = 0). They are shown to be equivalent in this study. That is, crack kinking takes place at the angle close to maximum G or GI (also minimum GII, with a value that is approximately zero). The average value of GIC obtained from bulk adhesive tests using compact tension specimens is shown to be an accurate indicator of the mode I fracture toughness of the kinking cracks within the adhesive layer. It is concluded that the crack in tri-material adhesively bonded joint tends to initiate into the adhesive along a path that promotes failure in pure mode I, locally. 相似文献
97.
98.
The analysis of a bimaterial medium with various notch opening angles has been carried out using boundary finite element method (BFEM) under arbitrary loading conditions. Introduced as novel method for stress concentration problems at geometrical discontinuities, cracks, bimaterial notches etc., the BFEM has been proved as numerically highly efficient. This has become more and more important because wedge type construction creates stress concentrations which may lead to crack initiation in many practical situations where multi-layered composite material is used, e.g. within aerospace, ship or automobile structures. So, the computational prediction of potential directions for crack initiation is essential for the knowledge of weak regions. All the analysis results are based on the hypothesis of Erdogan and Sih and have been verified by the well established finite element method. Results for potential crack initiation angles of both homogeneous and bimaterial media are presented with multiple examples of different wedge angles and different loading combinations. 相似文献
99.
A routing algorithm for a single transfer crane to load export containers onto a containership 总被引:5,自引:0,他引:5
It is discussed how to route transfer crane during loading operation of export containers in port container terminal. We determine the number of containers which transfer crane picks up at each yard-bay as well as the sequence of yard-bays which transfer crane visits during the tour. The objective is to minimize the total container handling time of the transfer crane including the set-up time at each yard-bay and the travel time between consecutive yard-bays. This routing problem is formulated as an integer programming. An efficient optimizing algorithm is also developed for the crane routing problem. 相似文献
100.
基于TDD-CDMA系统前向与反向链路的互易性,以反向链路的波束成形为基础,分析了在不对称传输情况下前向链路波束成彤、功率控制及信号空间特征之间的联系。首先将前向链路波束调节权值的求解转换为标准的半定规划问题(SDP),得出权向量与阵列误差之间的近似表达式;其次引入调节权值与加栽量之间的迭代关系,从而得出了阵列响应与自适应加载水平之问的函数表达式及前向链路最优功率分配方案;最后给出了仿真验证及分析。 相似文献