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本文介绍了改进的光弹性贴片盲孔法测残余应力的计算公式,并与西田正孝计算公式进行了对比。进行了单向均匀拉伸板模拟残余应力试验验证,以及对接焊板残余应力实测。 相似文献
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大错位量散斑干涉法测量残余应力 总被引:1,自引:0,他引:1
本文提出大错位量激光散斑干涉法结合钻孔法测量残余应力,对单向拉伸残余应力进行了测量,试验结果与理论解非常吻合,并且实现了对真实构件表面残余应力的测量. 相似文献
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动车组转向架构架载荷状况复杂, 实际运用条件下包含多个基本载荷系, 因此转向架构架局部位置的总损伤是若干载荷系在该位置相应损伤的累积; 转向架构架实验谱是考核动车组构架寿命的关键手段, 在没有实测载荷的条件下如何编制实验谱是本文的研究目标.本文首先对转向架构架承载系统的线性假设、稳定假设及典型假设进行了确认研究; 然后根据长期实测线路仅有的动应力数据, 将转向架构架典型应力分区域编制应力谱; 其次根据构架受力特点对构架建立载荷系, 在试验台中标定各个载荷系下的载荷应力传递关系, 并将区域典型测点的最大标定系数作为该区域的载荷应力传递系数; 然后基于损伤一致性原则建立优化函数, 并将获得的载荷应力传递系数矩阵代入优化函数, 得到一种适用于由线路实测动应力大数据推导出实验载荷谱的方法. 试验结果证明该方法具有较高的精度, 对构架关键部位的考核实现了典型区域全覆盖; 在中国线路运用工况下, 相比国际通用规范, 该方法对所有典型区域做到损伤再现, 所编制实验谱对转向架构架的考核更具有适用性. 相似文献
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《力学学报》2021,(1)
动车组转向架构架载荷状况复杂,实际运用条件下包含多个基本载荷系,因此转向架构架局部位置的总损伤是若干载荷系在该位置相应损伤的累积;转向架构架实验谱是考核动车组构架寿命的关键手段,在没有实测载荷的条件下如何编制实验谱是本文的研究目标.本文首先对转向架构架承载系统的线性假设、稳定假设及典型假设进行了确认研究;然后根据长期实测线路仅有的动应力数据,将转向架构架典型应力分区域编制应力谱;其次根据构架受力特点对构架建立载荷系,在试验台中标定各个载荷系下的载荷应力传递关系,并将区域典型测点的最大标定系数作为该区域的载荷应力传递系数;然后基于损伤一致性原则建立优化函数,并将获得的载荷应力传递系数矩阵代入优化函数,得到一种适用于由线路实测动应力大数据推导出实验载荷谱的方法.试验结果证明该方法具有较高的精度,对构架关键部位的考核实现了典型区域全覆盖;在中国线路运用工况下,相比国际通用规范,该方法对所有典型区域做到损伤再现,所编制实验谱对转向架构架的考核更具有适用性. 相似文献
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本文提出了一种转动结构用于铜合金冷轧板带残余应力检测以及面内形变的测量方法。用有限元法(FEM)对转动结构作了设计并优化以提高测量灵敏度、便于用线切割制备试样。在专用试验台上模拟残余应力释放,用应变仪和工具显微镜同时测量转动结构对应的应变和变形量输出,标定结果显示转动结构对残余应变检测灵敏度为0.49μm/10-6、相对偏差<4%,与FEM计算结果相吻合。分别用转动结构和化学腐蚀法对铜合金板带C194(600mm×0.23mm)纵向残余应力作了检测,两种方法的试验结果非常接近。本文提出的转动结构在精密铜合金板带残余应力和变形检测中具有测量准确、便捷、检测效率高的特点。 相似文献
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用逐次残余法分析了聚乙烯和聚苯乙烯缓冲材料的应力松弛试验数据.结果表明可用有限个并联的Maxwel模型来表示这两种材料的应力松弛试验曲线. 相似文献
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根据挤压强化孔残余应力场具有衰减的特征,对LY12cz和LC4cs两种铝合金材料在不同条件下挤压孔的残余应力衰减规律进行了有损试验测定。通过试验得到的有限数据,建立了一种指数型拟合函数模型,并可作为估计残余应力循环衰减值的一种工程简化方法。本文的研究结果为改善强化设计的失效预测方法提供了依据。 相似文献
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本文用激光散斑剪切干涉法及钻孔释放法直接测取释放应变,进而计算残余应力.用模拟铝合金试件测取残余应力,条纹清晰,试验结果与理论解一致性较好。 相似文献
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建立了考虑线路弹性并视转向架构架为柔体的三节车辆组成的列车通过道岔运行的列车/线
路模型. 分析了列车通过道岔时作用于转向架构架上的动载荷,将动载荷通过程序
FEMBS{-1}转化为适用于FE程序的文件并由ANSYS软件分析整个构架的应力分布及最大应力时间历程变化等. 分析对比了列车及单节车辆的仿真结果并与线路动应力试验结果进行了对比. 研究认为列车通过道岔时各构架的拉、压动应力幅值变化各异且在岔心处大于单辆车的相应值,表明单辆车模型适用于初步的计算分析,欲详细分析构架的结构性能应采用多车模型. 根据动应力频谱分析可知,构架的动应力可分为3个频域区,分别对应由直线驶入道岔的曲线上、岔心和岔尖处及构架固有振动频率附近的弹性振动区. 相似文献
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Measurement of Applied Stresses and Residual Stresses on a Residual Stress Model by Applying Two Different Loads 总被引:1,自引:0,他引:1
T. Kihara 《Experimental Mechanics》2011,51(8):1275-1283
Applied stresses on a residual stress model have previously been obtained by measuring the residual stresses and the resultant
stresses generated by applying a load. The present paper reports that the applied stresses and the residual stresses on the
residual stress model can be obtained by measuring two resultant stresses generated by applying loads of two different magnitudes.
In the proposed method, the residual stresses need not be obtained from the residual stress model before applying a load.
The residual stress model used to test the proposed method is a circular disk with frozen stresses that is subjected to a
diametral compressive load at a certain angle. The applied stresses and the residual stresses on a residual stress model were
experimentally and precisely obtained by digital photoelasticity using linearly polarized light. 相似文献
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P. Pagliaro M. B. Prime J.S. Robinson B. Clausen H. Swenson M. Steinzig B. Zuccarello 《Experimental Mechanics》2011,51(7):1123-1134
The traditional contour method maps a single component of residual stress by cutting a body carefully in two and measuring
the contour of the cut surface. The cut also exposes previously inaccessible regions of the body to residual stress measurement
using a variety of other techniques, but the stresses have been changed by the relaxation after cutting. In this paper, it
is shown that superposition of stresses measured post-cutting with results from the contour method analysis can determine
the original (pre-cut) residual stresses. The general superposition theory using Bueckner’s principle is developed and limitations
are discussed. The procedure is experimentally demonstrated by determining the triaxial residual stress state on a cross section
plane. The 2024-T351 aluminum alloy test specimen was a disk plastically indented to produce multiaxial residual stresses.
After cutting the disk in half, the stresses on the cut surface of one half were determined with X-ray diffraction and with
hole drilling on the other half. To determine the original residual stresses, the measured surface stresses were superimposed
with the change stress calculated by the contour method. Within uncertainty, the results agreed with neutron diffraction measurements
taken on an uncut disk. 相似文献
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压力机焊接残余应力的状态分析 总被引:2,自引:0,他引:2
对 2000k N 及 1500k N 压力机焊后残余应力状态进行了测试分析,并对用振动法和热处理两种方法进行消除残余应力的效果进行了现场测试及对比分析。 相似文献
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The incremental hole-drilling technique (IHD) is a widely established and accepted technique to determine residual stresses in peened surfaces. However, high residual stresses can lead to local yielding, due to the stress concentration around the drilled hole, affecting the standard residual stress evaluation, which is based on linear elastic equations. This so-called plasticity effect can be quantified by means of a plasticity factor, which measures the residual stress magnitude with respect to the approximate onset of plasticity. The observed resultant overestimation of IHD residual stresses depends on various factors, such as the residual stress state, the stress gradients and the material’s strain hardening. In peened surfaces, equibiaxial stresses are often found. For this case, the combined effect of the local yielding and stress gradients is numerically and experimentally analyzed in detail in this work. In addition, a new plasticity factor is proposed for the evaluation of the onset of yielding around drilled holes in peened surface layers. This new factor is able to explain the agreement and disagreement found between the IHD residual stresses and those determined by X-ray diffraction in shot-peened steel surfaces. 相似文献
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A. N. Guz 《International Applied Mechanics》2005,41(8):944-955
The ultrasonic nondestructive method for determining stresses in near-surface layers of solid bodies is based on the laws
governing the propagation of elastic surface waves in bodies with initial (residual) stresses. These laws are established
within the framework of the linearized three-dimensional theory of waves in bodies with initial (residual) stresses. The dispersion
equations in associated problems are solved by computational methods. The nondestructive method and measuring instruments
and devices are described. Some examples of nondestructive determination of welding-induced residual stresses and operating
stresses in near-surface layers of materials are presented
Presented at the International Conference on Computational and Experimental Engineering and Sciences (ICCES'04) (Madeira,
Portugal, July 26–29, 2004) and published in the journal Computer Modeling in Engineering and Sciences (CMES).
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Published in Prikladnaya Mekhanika, Vol. 41, No. 8, pp. 130–144, August 2005. 相似文献