共查询到10条相似文献,搜索用时 62 毫秒
1.
2.
In an earthquake occurring directly under a city, such as the Hanshin–Awaji great earthquake, the first axial longitudinal
impact induced from the source may create fatal damage to the architectural columns. This phenomenon has been confirmed by
a theoretical analysis based on elastic wave propagation in columns fixed at both ends. In this paper, the stress intensification
behavior in the columns under axial impact is verified by the high-speed photoelastic experiments in combination with semiconductor
strain gage and by the theoretical analysis of the longitudinal stress wave analysis method. 相似文献
3.
The development of torque-induced shear stresses in the presence of slippage, and the residual stresses remaining after torque-induced
slippage, are analysed using frozen-stress photoelasticity. Shaft/ring specimens were manufactured from epoxy photoelastic
material and were assembled by shrink-fitting prior to being loaded under various regimes, notably the application and release
of a torque load. The interface pressure was predicted from Lamé thick cylinder theory, and was also estimated by fitting
the Lamé model to the measured stress distributions. The distributions of interface shear stress were calculated from averaged
photoelastic data, and compared with the results of a dislocation-based model and with a nonlinear finite element model. For
a torque loaded specimen there was good agreement between experimental, theoretical and FE data. Another specimen was loaded
in torque then unloaded, with results showing the expected features of slippage and residual stress.
相似文献
J. D. BookerEmail: |
4.
5.
本文对应力波载荷(加载速率KI≥105MPa m/s)作用下,动态断裂韧性测试技术中的非光学方法进行了较全面和较系统的研究,比较了各自的优缺点,并对不同方法的可靠性和适用范围进行了分析. 相似文献
6.
In this paper, the theoretical solution developed by Vaughan and Wu for the stress analysis of a circular disk with a radial
edge crack extending to its center is validated by photoelasticity. The photoelastic results include the fullfield isochromatics
as well as measurements of the maximum shear stress at a number of test points. Additionally, the experimental stress intensity
factor is extracted from the photoelastic data by Irwin's two-parameter method. Good agreement is observed when the theoretical
stress field and stress intensity factor are compared with the experimental results. It is concluded that the Vaughan-Wu solution
can be confidently applied in fracture mechanics analyses. The application of such a solution to the stress analysis of two-dimensional
bodies with complex geometries subjected to complex loading is also noted. 相似文献
7.
8.
P. Rizzo 《Experimental Mechanics》2006,46(3):297-306
In recent years methods based on guided ultrasonic waves gained increasing attention for the nondestructive evaluation and
the health monitoring of multi-wire strands used in civil structures as prestressing tendons and stay cables. The study of
wave propagation properties in such components has been challenging due to the load-dependent inter-wire contact and the helical
geometry of the peripheral wires. The present paper addresses an experimental investigation on the ultrasonic wave propagation
in seven-wire strands loaded at different stress levels. Wafer piezoelectric sensors are employed in a through transmission
configuration for the generation and detection of stress waves. The response of the lowest-order longitudinal mode is studied
at different levels of load. Those ultrasonic features, associated with the transmitted ultrasonic energy, sensitive to the
variation of applied load are identified and discussed as possible means of a load monitoring. 相似文献
9.
10.
扁挤压筒的挤压力及应力场的光弹性分析 总被引:3,自引:3,他引:3
扁挤压筒是挤压大型铝壁板的重要工具,也是关键技术之一。与圆挤压筒相比,由于扁挤压筒型腔的线型特殊,理论计算相当困难,很难有精确的理论解。同时,非中心对称的型腔使挤压力的分布也不均匀,使得以均匀分布挤压力作为边界条件的数值计算产生了相应的误差,也使理论计算更加困难。本文制作了1:18的环氧树脂扁挤压筒整体模型,用低弹模的环氧树脂材料作挤压材料模拟挤压工况并将应力加以“冻结”,然后通过光弹性实验研究分析了挤压筒挤压时挤压力的分布特点以及筒体内部的应力场情况。结果分析得出:挤压力沿型腔高度大体上是均匀分布的,但沿型腔周向有着明显的变化;并在型腔的长轴位置出现应力集中。该实验结果为扁挤压筒的强度计算及结构设计提供了参考依据,也与数值分析解起到相互佐证的作用。如果把扁挤压筒的受力模型简化成中间带椭圆孔的无限大平面的弹性力学模型,理论最大应力值与实验结果比较接近。 相似文献