For s-dependent systems, reliability models capable of reflecting the effect of failure dependence, i.e. the so called "common cause failure" are in demand, since the system reliability depends not only on the reliabilities of the individual components but also on the interactions among the component failures. Based on the attribute of system failure, the meaning of order statistics, as well as the mechanism of failure dependence, this paper developed s-dependent system reliability models by incorporating order statistics of component strength into load-strength interference model. The models simply characterize the fact that series system fails as long as the applied load exceeds the first (the minimum) order statistic of component strength, parallel system (with n i.i.d. components) fails when and only when load exceeds the nth (the maximum) order statistic of component strength, and k-out-of-n (F) system fails if load exceeds the kth order statistic of component strength. Since no assumption about s-independent failure was applied, the models are in a position to reflect the effect of failure dependence which may bring about common cause failures. To evaluate the reliability of general system comprising of non-i.i.d. components, an extended load - strength order statistics interference model was presented, too.

Metal strain gauges need to be designed differently from strain gauges made from silicon. In this paper equations are derived that allow us to calculate the resistance change of metal strain gauges as a function of the position on a thick diaphragm, a thin membrane and a disc simply supported at the rim. The results of finite element calculations presented reveal that large deviations from these equations occur for strain gauges on thin membranes made of soft materials.

The issue of information loss in the process of system reliability modeling through conventional load-strength interference analysis is discussed first, and the reason why it is impossible to construct dependent system reliability model simply by means of component reliability index is demonstrated. Then, an approach to modeling the reliability of dependent system with common cause failure (CCF) is presented. The approach is based on system-level load-strength interference analysis and a concept of 'conditional failure probability of component' as well. With the opinion that load randomness is the direct cause of failure dependence, a discrete type system reliability model is developed via the conditional component failure probability concept. At last, the model' s capabilities to estimate system reliability with CCF effect and to predict high multiplicity failure probability based on low multiplicity failure event data are proved.

对TC2钛合金焊接接头进行硬度测试以及拉伸、疲劳对比试验，并观察全部疲劳断口，分析焊接接头光滑试样的疲劳性能与影响因素。结果表明，焊缝区的硬度最高，约高于母材50HV，塑性较差，焊缝中的微观焊接缺陷是不可避免的，是影响焊接接头疲劳寿命的主要因素；热影响区的硬度较低，塑性较好，其拉伸强度是焊接接头部位的最薄弱区，但却有较好的疲劳性能。在99%可靠度的前提下，焊接接头的疲劳寿命约为母材寿命的46%。

The Leak-Before-Break (LBB) case of pressure vessels and piping is achieved with the sufficient margin between detectable leak and catastrophic break. Therefore, the respective characteristic crack sizes, i.e. leak size (the crack size at which leakage amount is great enough to be detected) and the break size (the crack size at which crack propagation becomes unstable) are two important governing parameters for the LBB case. In multiple crack situations, the initial crack distribution and crack coalescence behavior are also LBB governing factors. The multiple crack condition related parameters would affect the LBB margin with the characteristic crack sizes together. The effects of multiple cracks on the LBB case, with respect to the different characteristic crack sizes are investigated in the present article by means of computer simulation. The simulation results show that, in multiple crack situation, the LBB margin is not so sensitive to characteristic crack sizes as in single crack situation.