查询词典 mechanical damage

A meso mechanical analysis has been conducted on a hot-rolling steel of 16MnR toinvestigate the effect of the elongated pre-damage voids on the subsequent damage evolution and fracture process under the maximum normal stresses with various directions. The analysis results show that, when the elongated voids due to the decohesion of the inclusions from base material are loaded subsequently, the local high stress and strain concentration around the voids and their interactions promote the growth of voids.

对热轧钢中的长条形初始损伤孔洞承受不同方向最大正应力时的后续损伤演化和断裂过程的细观有限元力学分析研究表明：热轧钢中的长条形夹杂物与基体剥离后形成的长条形孔洞在后续加载中，其周围产生的局部高应力应变集中及其相互作用，使孔洞长大。

Macro phenomenon is the macro representation of meso-phenomenon. In order to find out the mechanical transmutation of porous media under impacting loading, disclose the effect of fluid phase in the process of damage, post-damage and the liquation of the solid phases, it has significant meaning to establish a new model on meso-level with real separate phases to study the mechanics behavior and action mechanism between two phases.

宏观现象是细观现象的宏观体现，因此为了真正了解多孔介质在荷载作用下力学性质的演变过程，揭示液体相在多孔介质破坏、后破坏以及固相液化中的作用，很有必要从细观的角度建立具有真正意义上的独立相的模型，从细观角度分析多孔介质中两相介质在强动荷载下的力学行为，揭示两相介质间的作用机理。

The tensile strength and the elastic modulus were assumed to obey Weibull and logarithmic normal distribution and the other mechanical parameters were taken as constant values in the simulations of three-graded-concrete supported beam. The random aggregate random parameters model was established, which is very close to the actual structure. The results show that the nonlinear behavior of higher homogeneous specimen appears later obviously; the influence of random distribution of elastic modulus on the mechanical character is very little in linear range, while great in nonlinear range; random distribution of tensile strength affects the strength and the damage threshold of concrete obviously.

对三级配混凝土简支梁进行数值模拟时，假定各相材料的抗拉强度和弹性模量服从Weibull、对数正态两种随机分布，其他力学参数取定值，生成和实际结构比较接近的随机骨料随机参数模型，数值模拟结果表明材料均质度较高的试件出现非线性行为的时间要明显滞后于均质度较低的试件；弹性模量分布的随机性对材料线弹性段力学性能的影响极小，而对非线性区域的影响较大；材料强度分布的随机性对混凝土的强度和损伤阈值有较大的影响。

Base on the problem of large quantity fatigue loads on corroded R.C. structure and small quantity study of its mechanical property, bending resistance fatigue test of corroded R.C. beams is discussed in this paper. The influence of stress ratio and re-bar weight loss ratio on bending resistance fatigue performance of corroded R.C. beams are researched, and the relation between strains of corroded re-bars and fatigue life of beams are obtained. The main research contents and conclusions are as following: 1. Under the fatigue loads, the overstrain of concrete approximately coincidences three stages strain development and accumulation rule, and the mechanical property of concrete is deteriorated. The fatigue damage of concrete is accumulated. The overstrain of re-bars increases and the increase rate decreases.

鉴于实际工程中大量存在腐蚀钢筋混凝土结构承受反复荷载作用，但其力学性能研究不多的问题，本论文进行了锈蚀钢筋混凝土梁抗弯疲劳试验，研究了应力比和钢筋锈蚀率对锈蚀钢筋混凝土梁抗弯疲劳性能的影响，得出了锈蚀钢筋的应变与构件疲劳寿命之间的关系曲线，主要研究内容及结论如下：(1)在循环荷载下，混凝土残余变形基本符合三阶段变形规律，力学性能劣化，疲劳损伤积累。

In order to describe mechanical properties of red sandstones under different water ratio, by means of statistical damage theory and strain-equivalence hypothesis statistical damage model of red sandstones with effect of water ratio considered is developed.

为了描述红砂岩随含水率不同，所反映出来的力学特性，本文运用损伤统计理论和Lemaitre应变等价性假说，推导出能反映含水率影响的红砂岩损伤统计模型。

Distribution region of EDZ and mechanical behaviors of rock mass are further evaluated by using damage model, and the result shows that damage variable is 0.6-0.8 for damaged zone, 0.4-0.6 for affected zone and 0.2-0.4 for slight affected zone. Finally, the slope excavation softening factor is introduced to Hoek-Brown empirical strength criterion, based on the deficiencies of using Geological Strength Index to estimate the rock mass mechanical parameter of EDZ.

对应实测开挖扰动区的分布范围和形状，可以近似确定开挖损伤区岩体的损伤值约在0.6~0.8以内，卸荷影响区岩体的损伤值约在0.4~0.6以内，轻微扰动区岩体的损伤值约在0.2~0.4以内；由此基于Hoek-Brown经验强度准则，引入开挖弱化因子，结合地质强度指标GSI，进行开挖扰动区岩体力学参数研究。

A continuous damage model of concrete is proposed based on simple mechanical model. The couple of volume and deviatoric nonlinear hardening, anisotropical damage, direction effects and differential failure forms can be described by this model.

基于 一个简单机械模型发展了混凝土的连续介质损伤模型，它可描述包含体积和偏量非线性变形间的耦合、强化、各向异性损伤及其方向效应，以及不同的破坏模式。

The results were found as following:(1) The damage value increases more significantly with the increase in PVF before 30% PVF, beyond which the increasing trend becomes gradually gentle.(2)Keeping the interphase strength and PVF unchanged, the damage increase with increasing moisture concentration in a nearly linear relation.(3)The results generated from the FCC model with consideration of the interphase debonding are in good agreement with the experimental data, meanwhile, the FCC model is also capable of predicting the critical load for the damaged and the undamaged dental composite subject too the 3-point flexural test.4 A 3D-fmite element analysis has been successfully exploited to examine the mechanical behavior of the restoration-tooth structure under the polymerization shrinkage and water sorption. It was found:(1) The low stiffness of the composite has the effect to limit the displacement occurring in the remaining tooth tissue. For lower interphase, the cuspal flexures are litter higher. The high interphase modulus acts as a \'shielding effect\' for stress transfer.

得到如下结论：(1)相同的吸湿性，在30％PVF(颗粒体积分数：Particle volume fraction，PVF)前增加PVF，层间脱胶损伤值显著增加；此后损伤值的增加趋于平缓；(2)保持层间强度和PVF不变，层间脱胶损伤随吸湿率的增加而接近线性增加；(3)FCC(面心立方：Face-centred cubic，FCC)模型层间脱胶损伤的预测结果和实验数据基本吻合；同时此模型可以用于预测牙齿填充材料三点弯曲实验的临界载荷。4、建立理想牙齿修复结构，利用有限元方法研究了同时考虑聚合收缩和吸湿膨胀耦合作用下的填充修复材料和粘结界面层材料性能对牙齿修复结构的力学行为的影响，得到如下结论：(1)低弹性模量的牙齿填充修复材料能限制天然牙组织的位移，但天然牙组织的位移与粘结界面层的弹性模量无关。

The damage of rocklike materials is complex. Some mechanical model can provide satisfactory results under simple loading. A few of models (Dragon's, etc) may describe the damage evolution of quasi-brittle materials in the condition of complex loading.

Dragon等人基于不可逆热力学框架建立的准脆性材料的各向异性弹性损伤模型，可以较好地描述岩石类准脆性材料在复杂加载路径下的的应力应变响应和损伤演化过程。

Mechanical problem basically is the o-ring damage, brine sealing damages, pump damage, piping and valves damage, not accurate instrument, etc.

机械问题主要是O形圈的损坏、盐水密封的损坏、泵的损坏、管道和阀门的损坏、不精确的仪表等。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。