一个密闭的液体闪烁体灌装系统

本文介绍长液体闪烁体的灌装装置。该装置的建立,保证了快中子位置灵敏谱仪作快中子小角度弹性散射截面测量的长期稳定性。对其它类似研究工作也可提供必要的实验条件。     

两斜交圆柱壳在内压作用下的弹性应力分析

本文讨论了两斜交圆柱壳在内压作用下的弹性应力分布。文中,首先研究了具有任意形状孔洞的被相贯壳(圆柱形容器)在内压作用下的弹性应力和位移。分析日于,采用曲线坐标(ξ,η),并使其中一个坐标ξ=ξ。与孔洞围线厂相重合。控制方程就是在此坐标系中的扁壳方程。当孔洞围线厂为椭圆时,所得的解是以Mathieu函数表示的复函数形式。然后,根据Flügge方程讨论了相贯壳(圆柱形接管)的、以边缘效应形式表示的应力和位移。最后,作者推导了相贯曲线处应满足的边界条件,作了数值计算,并将计算结果与实验作了比较。     

Experimental Values for the Elastic Constants of a Particulate-Filled Glassy Polymer

Young’s modulus and Poisson’s ratio have been measured simultaneously on a series of particulate composites containing volume fractions of filler up to 0.50. The composites consisted of small glass spheres imbedded in a rigid epoxy polymer matrix. The measured values were compared with theoretical values calculated from current theories. A recently generalized and simplified version of van der Poel’s theory provided the best agreement. It predicted values of Young’s modulus for composites with filler volume fractions up to 0.35. Measured values of Poisson’s ratio exhibited scattering, but were consistent with values calculated from van der Poel’s theory.     

Nonlinear Dynamic Finite Element Analysis of Thick Transversly Flexible Sandwich Panel on Elastic Foundation with Account of Damage Progression in Time. Part 1. Three-Dimensional Formulation and Two-Dimensional Plate Theory

In order to construct a plate theory for a thick transversely compressible sandwich plate with composite laminated face sheets, the author makes simplifying assumptions regarding distribution of transverse strain components in the thickness direction. It is assumed that the transverse strains, i.e., _xz, _yz, and _zzdo not vary in the thickness direction within the face sheets and the core, but can be different functions of the in-plane coordinates in different sublaminates (the face sheets and the core). An algorithm, which takes account of damage progression in dynamic problems, is incorporated into the computational scheme based on the geometrically nonlinear formulation, and is applied to failure analysis of a sandwich plate under ground impact.__________Translated from Problemy Prochnosti, No. 2, pp. 92 – 106, March – April, 2005     

Behavioural change phases of different stakeholders involved in the implementation process of ergonomics measures in bricklaying

The objective of this qualitative study was to assess whether a hypothesised sequential order of behavioural change phases would be fulfilled in different groups of stakeholders involved at the start of a process to implement ergonomic [corrected] measures in bricklaying teams. The measures include trestles, bricklaying scaffolds, mast climbing work platforms [corrected] and cranes. The behavioural change phases were: (1) being aware of measures, (2) understanding measures, (3) wanting measures, (4) intention to buy or hire measures, (5) ability to use measures, (6) using measures (experience), and (7) continuing to use measures. Structured interviews were conducted to examine the change phases in two groups of stakeholders (employers/work planners (n=11) [corrected] and foremen/bricklayers (n=9) [corrected] from nine companies) thought to be relevant in the decision to adopt and use the ergonomic [corrected] measures. The results show that the fulfilled behavioural change phases differ between individual stakeholders, groups of stakeholders, companies and also between ergonomic measures. The hypothesised order of fulfilled consecutive behavioural change phases for individual stakeholders has not been confirmed by this study. The relationship between [corrected] fulfilled and unfulfilled change phases by each stakeholder (group) and actual use of each ergonomic measure requires further study, so as to improve the selection of suitable implementation strategies [corrected]     

Brillouin spectroscopy of oriented PMMA

The elastic properties of oriented PMMA have been re-investigated by Brillouin spectroscopy. Most of the elastic stiffness tensor components are presented. The order parameter P₂ has been determined as a function of orientation and is compared with P₂ deduced from other methods. Previously reported elastic anomalies of oriented PMMA^7a,b could not be confirmed     

Traffic Source Characterization：Considering Real Demands of Communication Attempts

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复合材料纤维/基体界面失效问题的参变量有限元数值模拟

本文利用参数拟二次规划法和非连续线弹性本构模型,构造了复合材料纤维/基体界面失效问题的细观力学模型并进行了有限元计算分析,得到了与实验相吻合的结果。     

弹性多臂系统动力分析

本文研究了机器人弹性多臂系统动力学建模问题。首先为了有效地削弱大的刚性运动位移与小的弹性变形即慢变量与快变量之间的耦合效应问题,采用了Tisserand 浮动坐标系、有限元理论及带λ乘子的拉格朗日方程建立了弹性多臂系统动力学方程;其次考虑了机器人上实际存在的集中质量和关节弹性对弹性臂运动的影响;然后通过代数——微分混合方程组的数值求解来分析弹性臂的动力响应,最后给出了机器人弹性双臂系统的动力响应算例。本文为弹性机器人的设计和振动控制提供了有益的参考。     

Fatigue of cold worked ribbed reinforcing bar—a fracture mechanics approach

A theoretical method for the prediction of fatigue life of structural members containing external stress raisers has been developed. The method is based on a linear elastic fracture mechanics approach to fatigue. The theory has been applied to fatigue of Torbar steel in concrete beams. The required parameters for such application were obtained from fatigue tests on samples and finite element analysis of cracked bars. Comparisons between the theory and experimental data taken from other investigations have shown that the theory predicts a reasonable lower limit fatigue life of Torbar in concrete beams. The theory has also successfully predicted the effect of the minimum stress on the fatigue life of this type of bar.