应力

Hypothesizing that the stress distributions don＇t refer to stressstrain history of explosive in pressing process ,the stress in the condition of steady load for charge of projectile body is analyzed and calculated by two methods: one is that the whole projectile body is divided into smaller lattices to solve ,the other one is that the whole projectile body is divided into smaller lattices firstly, and then local lattices are bridged according to the need for solving.

假设药柱的应力分布不涉及压制过程炸药的应力一应变历史，采用两种方法对装药弹体在静载荷下的应力进行分析计算，一种是将整个弹体划分成较小的网格进行求解，另一种是先对整个弹体进行网格划分，然后根据求解的需要对局部网格进行加密。

Objective By way of measure the stress of elastomeric ligatures periodically after three different loads were load on, to evaluate the stress relaxation of it.

内容摘要：目的通过定期测量结扎橡皮圈负载后应力的变化，研究它应力松弛的过程及在不同负载下应力松弛率的异同。

An earthquake nucleates and happens not only as a result of increments and changes in back ground tectonic stress field, but also as a result of stress changes in the focal region, so seismic wave velocity and attenuation contain information on stress changes of the Earth's interior as a result of changes in the physical state of materials.

地震的孕育和发生除了与区域背景构造应力的增长变动有关，也是震源区应力增长及破裂发展的结果。因此地震观测资料必然携带有震源区应力应变增长及破裂发展的信息。

But for the TEC overmatching, the residual stress σ〓 in the weld center is also related with the strain hardening coefficient H W of the weld metal. The residual stress σ〓 in the weld center got to the yield strength σ〓 increases little when the H'w is lower and somewhat exceeds the σ〓 when the H'w is higher.

而高胀匹配时的焊缝中心纵向残余应力σ〓还与焊缝金属应变硬化指数H〓有关，H〓较低时，焊缝中心纵向残余应力σ〓在达到焊缝金属屈服强度σ〓后不再升高；H〓较高时，焊缝中心纵向残余应力σ〓可超过焊缝金属屈服强度σ〓。

The results showed that when retrogressed by electrical current heating at 200 ℃ the tensile strength in re-aged 7A04 alloy extrusion bar of 60 mm in diameter reached 620-640 MPa and a uniform elongation appeared from central part to surface layer of the sample while the fracture time in test of resistance to stress corrosion under a load stress of 375MPa in 3%NaCl+0.5%H2O2 corrosion solution was greater than 30 d.

结果表明，直径60 mm的7A04铝合金棒材在200℃电流直接加热回归后再时效，从心部到表层的拉伸强度为620-640 MPa，延伸率均匀一致；在3%NaCl+0.5%H2O2水溶液介质中和375 MPa应力下的应力腐蚀断裂时间大于30d，而辐射式加热回归的为575 MPa，延伸率从心部至表层表现极不均匀，应力腐蚀断裂时间只有19 d。

The results showed that when retrogressed by electrical current heating at 200℃the tensile strength in re-aged 7A04 alloy extrusion bar of 60 mm in diameter reached 620- 640 MPa and a uniform elongation appeared from central part to surface layer of the sample while the fracture time in test of resistance to stress corrosion under a load stress of 375MPa in 3%NaCl+0.5%H_2O_2 corrosion sol...

结果表明，直径60 mm的7A04铝合金棒材在200℃电流直接加热回归后再时效，从心部到表层的拉伸强度为620-640 MPa，延伸率均匀一致；在3%NaCl+0.5%H_2O_2水溶液介质中和375 MPa应力下的应力腐蚀断裂时间大于30 d，而辐射式加热回归的为575 MPa，延伸率从心部至表层表现极不均匀，应力腐蚀断裂时间只有19 d。

Based on present researches,by means of modern measurement and analysis techniques,systemic laboratory experiments,field investigations and through theory researches were conducted.And following are the major points and achievements presented in this dissertation:①The micro-convexity on fracture plane was studied.Analyzing and comparing the static attribute and dynamic variation of natural fracture with the artificial,untreated fracture,artificial and scabbled fracture as well,making out the criteria that artificial and scabbled fracture simulate natural fracture.②We take the effect of all the three primary stresses and stress invariant into account in the Lade-dbl yield criterion,which can preferably reflect all the yield and destruction characteristic of the rock material.

结合裂缝性储层应力敏感性研究现状，利用现代化测试手段，通过系列的室内实验以及深入的理论探讨，本文取得的研究成果包括以下几个方面：①从裂缝面上的微凸体入手，分析和对比了天然裂缝、人工但未经过处理的裂缝，以及经过粗化处理以后的人工裂缝的静态特征和动态变化，指出了经过粗化处理以后的人工裂缝模拟天然裂缝的依据；②Lade双曲服面屈服准则考虑了所有三个主应力或应力不变量对屈服与破坏的影响，能够较好的反应岩石材料的所有屈服和破坏特性。

It is found that there is strong effect of 3D constraint on the continuities and singularities of radial stress and equivalent stress.

计算结果表明，三轴应力约束对裂尖场的分布，尤其是对径向应力σr和有效应力σe有重要影响。

In the depth scope ranging from 1100 meters to 3500 meters, the direction of the middle principal stress becomes vertical.The simulation result, from the modelling of the Kun 2# drill and its vicinities, suggests that the vertical stress variation is relatively small in the place 3 to 7 times of the drill diameter from the well wall, but the horizontal stress varies in some trend. Moreover, the direction of the minimal stress component and the remote loading pressure take place large deviation in southeast direction.

而对昆2井及其周边地区建立了子模型进行模拟的结果显示，在距井壁3～7倍的地方，垂向应力变化相对较小，但水平应力则发生了不同程度和趋势的变化，另外，最小应力分量的方向与远源加载的压力在南东向发生了较大的偏转。

The objectives of this paper were to investigate the simulation and design of continuous multiple-station rolling forming process for a U-Section Steel Bar by CAE software-DEFORMTM Due to the limitation of elements number using a short strip 120mm went through all the stations to simulate the real continuous rolling forming on factory The roller gap was fixed as 0 30mm roll speed was 20 rad/sec and progressive angles were all equal for each rolling process which were the formed angle divided by by the number of station Three rolling processes were selected with 6 9 and 12 stations respectively During simulation processes two cases occurred Case A the strip was through a single station Case B the strip across two stations Because the strip laterals side was stretched and twisted during the process The model of case B closer to the practical process than case A and the calculated stress and strain on the tip of U section for case A were lower than these for case B by up to 15% From the result of case B for each process the stress for 12-station process was smallest 9-station process second and 6-station process next Because less-station can save larger cost and forming time but the bigger stress and strain for 6-station caused wrinkles on lateral sides not found on 9-station and 12-station Therefore 9-station process was a more suitable design than 12-station process smaller stretched and twisted and stress The progressive angles for 12-station was 7 5?

本文主要是以DEFORMTM有限元素软体模拟U型钢片连续道次成型与单一道次成型以确认单一道次模拟的是否可取代连续道次模拟之研究。因DEFORMTM 软体对於网格元素上的限制故使用较短素材120mm通过所有的成型站以模拟工厂实际连续成形方法。辊轮间隙固定为0 3mm；辊轮转速为20 rad/sec；弯曲角度的方法为将成型角度平均除以成型站数。有三种辊轮成型方式被选择分别为6站，9站，与12站。在模拟的过程中有两种现象会产生 Case A，素材通过单一成型站。Case B，素材会通过两个成型站。因为在模拟过程中素材的两端会有拉应力与扭力。Case B的模拟比Case A像实际的制程，并计算应力与应变在U型断面的Tip部中可发现Case A比Case B低约15%。从Case B的每站的结果可以得知，12站的成型应力最小，9站次之，6站最后。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。