基于ABAQUS的显式动力学分析方法研究

显式动力学(The Explicit Dynamic)是针对隐式求解器的一个补充,其分析方法对于求解广泛、各类非线性结构力学问题是一个非常有效的工具,显式方法中的单个增量步取决于模型的最高固有频率,与持续时间、载荷类型无关。ABAQUS/Explicit主要用于碰撞、接触以及失效分析。探讨了ABAQUS显式动力学的基本理论、求解的问题,对显示动力学分析方法中的求解算法、稳定时间极限和能量平衡问题进行研究,给出了显示动力学分析的一般性分析方法。通过案例验证了该方法的可行性,应用该方法可有效解决实际工业生产中的碰撞问题、复杂的接触问题以及复杂的后屈曲问题,可为显式动力学分析方法应用于工程实践奠定理论与方法基础。     

秦山核电厂燃耗深度对DNBR限值的影响分析

本文研究了在秦山核电厂批平均卸料燃耗深度超过原定限值的情况下，为保证电厂的安全运行对DNBR限值进行重新确认的问题。研究过程中，综合考虑了由燃耗加深所引起的核焓升因子的变化和棒弯曲这两种效应对DNBR限值的影响。结果表明，对秦山核电厂而言，在批平均卸料燃耗超过原定限值的情况下，维持原DNBR限值不变仍是安全可行的。     

A CONSTITUTIVE MODEL FOR ELASTIC-PLASTIC DEFORMATION UNDER CYCLIC MULTIAXIAL STRAINING

Abstract— The yield criterion is interpreted as defining the metric of the stress space. Hydrostatic stresses correspond to null geodesies. The plastic strain increment represents a normal projection of the increment undergone by a certain scalar function (hardening function) which depends only on the distance between stress points. This establishes a flow rule formally equivalent to the Prandtl-Reuss equations. Consideration of un-loading processes leads to the analysis of equivalent paths and to the definition of a generalized length or separation which provides a new representation of kinematic hardening.     

微波单片集成电路的成品率优化

采用建立管芯等效电路模型、灵敏度分析以及统计勘探法对微波单片集成电路进行成品率优化，并编制了软件，加入到ＧａＡｓＩＣＣＡＤ系统中。应用该软件对Ｘ波段低噪声ＭＭＩＣ、超宽带ＭＭＩＣ放大器进行了设计，成品率有较大的提高，电路性能有所改善。     

Prediction of Undrained Sinkhole Collapse

Sinkholes are surface depressions or shafts resulting from the collapse of a submerged cavity in soil. The cavities that lead to sinkholes form as a result of underlying geology in limestone areas, or as a result of human activity such as mining or leakage from a sewer. The formation of sinkholes is often sudden and can lead to extensive damage and loss of life, especially in urban areas. Much of the literature on the subject of sinkhole formation is empirical in nature, often being associated with specific locations. This paper presents the results of a study, using numerical modeling, of the undrained stability of the submerged cavities that lead to sinkhole formation. Finite-element limit analysis techniques (using programs developed at the University of Newcastle) are used to obtain upper and lower bound values of a suitable load parameter, which bracket the exact solution. The results are compared to analytical solutions, both from literature and derived independently.     

深井重泥浆弱凝胶工艺技术初探

重泥浆强凝胶体系对钴井会产生不利影响。笔者结合川东地区的实际情况,分析了重泥浆强凝胶形成的原因和重泥浆弱凝胶的形成机制,提出了形成重泥浆弱凝胶体系的核心和设计原则,总结出了一套以正确使用泥浆添加剂并配合强有力的固控措施为主的成套深井重泥浆弱凝胶工艺技术,介绍了这套技术在川东地区的应用情况。实践证明,少用甚至不用泥浆降粘剂就可获得并维持尽可能低的静切力,使τ_s,10s为0.5—6Pα、τ_s,10min为2—12.5Pα。     

IEA joint trials: New lessons from old plantations

Two international trials of potential biomass species families and clones planted in 1985 have been analyzed to determine changing patterns in growth, diseases, and insects. In the Swedish trial, with close spacing and short rotations, Salix viminalis clones gave the best average yield of 17.4 Mg/Ha/yr on the first coppice rotation. In the Minnesota, USA trial, with wider spacings and a longer rotation Populus alba hybrid clones gave the best average yields of 5.5 Mg/Ha/yr. The most important disease and insect problems encountered were Septoria musiva stem cankers on some Populus clones; frost die back in some Salix clones; and the leaf blotch miner, Fenusa dohrnii, on most Alnus families. Recommendations for future international cooperation in field trials are presented.     

Ultrasonic nondestructive evaluation of fibre-reinforced composite materials — a review

A framework is presented for examining the effectiveness of limiting and modelling arguments used in the analysis of fluid flows. It consists of examining the consequences of the arguments on the flow problem as a whole and breaking down the limiting/modelling process into a sequence of steps and associated sequence of flow problems, termed here as ‘lidels’. The notion of validity of lidels is given. Several examples are given to explain the present approach. Invited general lecture at 3rd ACFM, Tokyo, September 1986     

一氧化碳对聚丙烯收率、结构的影响

分析研究了Montell(Himont)聚丙烯工艺中CO对聚丙烯收率、产品结构的影响。     

舞钢扁钢锭咬边参数的确定

本文根据我公司自产的11.7t及13.34t扁钢锭在4200mm轧机生产过程中,运用正交试验方法,合理应用咬边参数的轧制方案,以此降低金属消耗。此方案使“咬入返回轧制”及“留尾轧制”新技术进一步得到完善,板形更加矩形,使锭一材成材率提高2％左右。