应力

Home position shear tests of slope rock, point loading tests and indoor AMD simulation action tests in XingQiao concave slope had show shearing strength and coherence between body layers of quartz sandstone decrease by 13.2%~21.3% after attacked by AMD, the angle of internal friction between layers is decreased by 5.0%~7.5%, in general, AMD affects the rocks mechanical property at range of 60~100m interior the perpendicular slop. Data analysis shows: 1 The actions to slope are major focused on zone of weakness, shearing strength of slope foot and AMD centre are reduced by 52% and 64.7% separately. 2 The explosion stress wave of long distance field has obviously increasing influence to disturbance amplitude value of slope with increasing of the slope height and distance, the response of the top of slope and fault region are obvious as well as damage effect; the foot of slope is with smallest disturbance amplitude value, the disturbance amplitude value of the step close to free face is obviously bigger than the interior of slope. 3 With the coupling effect of the AMD and explosion loading, the stress distribution inside of slope mainly presents characters of explosion stress field; the area affected by AMD becomes a weak area of shearing stress.

新桥深凹露天矿边坡岩体的原位剪切试验、点载荷试验、室内模拟AMD作用试验表明：AMD蚀化后的石英砂岩，岩体层面间的抗剪强度和粘聚力减小的幅值约为13.2%~21.3%；层面间内摩擦角减小幅值在5.0%~7.5%之间；AMD一般影响垂直边坡体内部在60~100m范围内的岩体力学性质数值分析表明：AMD对边坡体的作用主要集中在弱化区域内，边坡体的底脚和AMD作用中心区域的剪切应力减少了52.0%和64.7%；(2)随着边坡体高度和距离的增加，远场爆炸应力波对边坡扰动幅值的增加趋势明显，边坡顶部和断层部位的响应突出，损伤效应明显；边坡底脚扰动幅值最小，临空面附近台阶的扰动幅值明显大于边坡体内部；(3)AMD与爆破荷载耦合作用后，边坡体内部的应力分布主要呈现出爆炸应力场的特征，AMD影响区域形成了一个剪切应力弱区。

The analysis results showed the main causes of reflection cracking of AC overlay on. PCC are the vehicle loading and temperature changes. With the increase of thickness of AC, the affection is not very clear. When the stress-absorbing interlays, which is 2~3cm and low modulus was added in the pavement, the stress in pavement system was reduced obviously.

数值分析结果表明：增加沥青层厚度可减小加铺层内的荷载及温度应力，但效果并不明显，而2～3cm厚的低模量应力吸收夹层的加入可有效地改善整个加铺结构的应力分布，大大降低加铺层底应力集中程度。

Stress relaxation of delignified and hemicellulose-removed wood was determined during periodic temperature change, and found that after 4-hour relaxation at 25℃ the stress curves hardly level off, at this time when increase temperature the stress immediately sharply fall and whereafter the decrease of temperature make stress rapidly recover again.

通过木材在温度周期变化过程中的应力松弛研究，发现，未处理木材和化学处理木材在25℃松弛4小时后，应力几乎水平下来，升温后，应力立即急剧下降，温度下降时，应力又急剧回复。

In the light of balance equation of disc's plane stress problems, the calculation formula of thermal and centrifugal stress for internal fixed loop under the axisymmetric temperature field has been deduced.

深入地探讨了面内热应力、适张度应力、离心应力之间的相互作用关系，揭示了圆锯片锯切失稳及适张度应力能够有效地提高锯切稳定性的机理所在。

The results indicate that the spalling behavior of oxide scale is the result of the inner and outer stress together,during rolling,the oxide scale cracks under the growth stress and thermal stress,at the same time the oxide scale also mainly undergoes alternative shearing stress in the rolling zone,the oxide scale spalls,then the reason of stripspalling is also analyzed.

结果表明：氧化膜剥落过程是内外应力联合作用的结果，轧制过程中氧化膜在长大应力和热应力作用下开裂，在轧制区内氧化膜还因受沿轧辊圆周方向的交变剪切应力作用而剥落。

Crack reasons for this are: the heating temperature is too high as a result of quenching or cooling in a hurry, the quality of thermal stress and metal volume changes in the organization of the anti-stress than the breaking strength of steel; the work of the original surface defects (such as surface micro-cracks or scratches) or the internal defect of steel (such as slag, serious non-metallic inclusions, white point, the residual cavity, etc.) formed in the quenching stress concentration; serious Decarburization and carbide surface segregation; parts after quenching Back lack of timely or tempering fire; processes in front of the stress caused by excessive cold red, forging folding, turning deep marks, sharp edges and corners, such as the oil groove.

造成这种裂纹的原因有：由于淬火加热温度过高或冷却太急，热应力和金属质量体积变化时的组织应力大于钢材的抗断裂强度；工作表面的原有缺陷或是钢材内部缺陷（如夹渣、严重的非金属夹杂物、白点、缩孔残余等）在淬火时形成应力集中；严重的表面脱碳和碳化物偏析；零件淬火后回火不足或未及时回火；前面工序造成的冷冲应力过大、锻造折叠、深的车削刀痕、油沟尖锐棱角等。

Grain boundary slidings happen in this alloy at the creep temperature of 200 ℃ and the deformation of this alloy is coordinated by intragranular slip and grain boundary sliding.

结果表明：在125~200 ℃蠕变温度下，当蠕变寿命接近100 h时，2024铝合金的蠕变应力随着温度的升高明显下降；与125 ℃相比，150 ℃时合金的蠕变应力下降9.3%，在175 ℃时合金的蠕变应力下降30.3%；当蠕变温度为200 ℃时，该合金的蠕变应力下降幅度达到45.8%；在125~175 ℃下，合金在蠕变过程中的变形机制主要为位错在晶内的滑移；在200℃时，合金晶界开始发生滑移，合金变形由晶界滑移与位错在晶内的滑移协调完成；在合金蠕变断面上存在大量微孔，随着蠕变温度的升高，微孔的尺寸明显变大，当微孔尺寸超过3 μm时，微孔对合金的断裂机制有显著影响；在125和150 ℃下，合金的蠕变断口呈现韧窝型穿晶断裂特征；在175和200 ℃下，合金的蠕变断口呈现沿晶断裂特征。

Also, the performance of four techniques, using different approximation to estimate the equivalent peak value of shear stress and strain were investigated for the purpose to determine the equivalent shear modulus, damping, excess pore water pressure and residual strain induced by seismic loading, in which the equivalent peak value was computed in terms of its standard deviation and the corresponding peak factor.

利用上述动力有限元程序分别对水平地基进行了总应力、不排水有效应力和排水有效应力随机动力响应分析，并通过4种不同的方法来计算地基的等效剪切模量、阻尼比、振动孔压和残余剪应力。

On the side of exterior deformation monitoring, this dissertation proposes and proves the utility monitoring scheme by using general ground monitoring technology and the method of simplification differentiation polar coordinate survey for large span space structure deformation monitoring. On the side of stress measurement, this dissertation proposes an new method of stress measurement suit for mass concrete triangular frame and discusses shrinkage and creep of concrete how to influence stress measurement, and sets up finally a process how to calculate concrete stress through data for piano wire sensors. Finally, on the side of cable forces measurement, this dissertation discusses principle and measurement technology of frequency method.

在外部变形测量方面，本文提出并验证了一套利用常规地面监测技术监测大跨度空间结构几何变形的实用方案及一种简化的差分极坐标测量方法；在应力测量方面，本文提出了一种适用于大型混凝土三角刚架应力监测的新方法，研究了混凝土的收缩徐变对应力测量的影响，并在此基础上建立了一套由振弦式传感器的测试数据推算混凝土结构应力的流程；在索力测量方面，本文探讨了频率法测量索力的原理及实用测量技术。

The results show that the ranges of secondary stress distribution have differences corresponding to different wall rock conditions of mining tunnel; but the principal stress distribution transits from compressive stress centralized in mining tunnel sidewall to tensile stress centralized in mining tunnel vault and floor.

研究结果表明，围岩条件不同的采矿巷道其二次应力分布影响范围有所差异，但围岩主应力总体上表现为由巷道边墙中下部位的压应力集中带逐步过渡到拱顶、底板一定范围内的拉应力集中带。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。