等径弯角挤压工艺(ECAEP)研究现状

等径弯角挤压是制备块状细晶材料的一种大塑性变形工艺，目前得到国内外高度重视．本文简要介绍了等径弯角挤压工艺的基本原理和变形特点，从理论上对其变形方式和机理进行了分析，并详细介绍了该工艺的应用领域。     

工程塑料在低压电器中的应用

工程塑料是低压电器行业应用比较广泛的材料,本文主要介绍了低压电器对工程塑性材料的要求及工程塑料的改性方法及效果,然后简单介绍电器专用料的性能、用途和工程塑料的发展方向。     

地下圆形洞室塑性回填效应的解析

本文对洞壁和衬砌间采用塑性材料回填的地下圆形隧道,由莫尔-库仑(Mohr-Coulomb)屈服准则,求得岩体、塑性回填材料与衬砌的内力及位移场的解析解。由某工程的计算值与实测值的符合程度表明,采用某种低模量的回填材料回填的方法,可以有效地减少衬砌的应力与位移。说明在一定条件下,这是一种有前途的工程措施。     

塑性材料“初生”“再生”屈服和强化中的相持新看法

通过国内外热轧钢筋机械性能检测现象及其数据分析，对塑性材料的典型代表－钢的轴向静力拉伸试验σ－ε－关系图提出“初生”屈服和“再生”屈服以及强化中相持阶段的新看法，并分析了产生的原因和特点。同时，对颈缩阶段中有关力学现象进行了简要的描述。本文对于塑性材料从“流变到破坏这一过程的变化机理，内部组织结构及其本构关系，形变能的变化规律，内能耗散与位错理论以及提高材料抗力等方面的研究具有重大的理论参考价值与     

日扩限玩具使用邻苯二甲酸盐

最近,日本玩具协会宣布,日本玩具安全标准（ST-2002）中受限制的邻苯二甲酸盐由2种增至6种,并且管制所有可塑性材料。     

斜井在表土段时底板承载力的初探

针对斜井在表土段出现的井壁断裂、开缝、顶底板及两帮强烈相对移近的情况，用太沙基公式建立了斜井底板承载力计算模型，并针对斜井底板倾斜的情况对计算模型作了一些修正。根据计算模型定性分析了影响底板承载力的参数，为提高底板承载力提供了理论依据。     

Critical condition study of borehole stablity during air drilling

The purpose of this paper is to establish the existence of the critical condition of borehole stability during air drilling. Rock Failure Process Analysis Code 20 was used to set up a damage model of the borehole excavated in strain-softening rock. Damage evolution around the borehole was studied by tracking acoustic emission. The study indicates that excavation damaged zone （EDZ） is formed around borehole because of stress concentration after the borehole is excavated. There is a critical condition for borehole stability; the borehole will collapse when the critical damage condition is reached. The critical condition of underground excavation exists not only in elastic and ideal plastic material but in strainsoftening material as well. The research is helpful to developing an evaluation method of borehole stability during air drilling.     

磨料射流高压管线材料冲蚀实验研究

磨料射流破岩钻径向水平井技术是近年发展起来的开发低渗油藏、提高原油采收率和煤层气产量的新方法。利用该方法破岩钻进过程中,高压管线内壁受磨料颗粒冲蚀严重的问题大大限制了该技术的推广与应用。为此,本文利用自建的冲蚀实验设备对塑性试件在水-砂液固两相流动中的冲蚀问题开展了实验研究,对包括冲击角、颗粒粒径、冲击速度和固相浓度四因素对试件冲蚀速率的影响规律进行了分析,并采用共轭梯度结合通用全局优化算法对所得实验结果进行回归分析,得到了冲蚀速率同上述因素的影响规律方程。     

综合材料

近年来工业设计的方法与技术与家具设计的结合越来越紧密,其中一个非常典型的特点就是塑性材料与木的结合。     

ADAPTIVE RIGID-PLASTIC MESHLESS GALERKIN METHOD AND ITS APPLICATION IN ANALYSIS OF EXTRUSION PROCESSES

Under the hypothesis of the rigid-plastic material,specific efforts are placed on the deve-lopments of the key simulation techniques of the meshless Galerkin method because of the complexity of the deformation process as well as the generality and atomization of the simulation procedures for non-steady state large deformation plastic processes,therefore,an adaptive rigid meshless Galerkin method is developed. The influence domain control method is used in the least square approximation by dynamic evaluation of the magnitude of the influence domain and the effective control of the amount and the positions of the points in the least square approximation in order to improve approxi-mation precision. The amount of the Gauss integration points in the discrete domain is maintained in a considerable magnitude in order to ensure the integration precision in the discrete domain. The length of the frictional boundary of the plastic deformation process may be getting longer when its deforma-tion is getting severe. Thus,the densities of the boundary points of some places get lower. The adap-tive boundary points setting method is employed to improve the approximation precision of the boundary points and enhance the constraint of the boundary condition by adaptive control of boun-dary point density. Some typical extrusion processes are analyzed,detail simulation results such as the deformation field,velocity field,effective strain field,effective strain rate field,the volume loss curve and load-stroke curve are obtained. The effectiveness of the method developed is demonstrated and the precision of the meshless simulation is proved by overall comparison with the results obtained by using the commercial software deform.