大变形的剪切型橡胶弹簧稳定性问题的探讨

从理论与工程相结合的角度剖析了一系剪切型橡胶弹簧失稳的力学原理,提出了改善橡胶弹簧稳定性的基本思路和可行措施,并在此基础上,对某型橡胶弹簧进行了优化设计及工艺制造改进。分析与试验表明,新结构、新工艺的橡胶元件与原产品相比,在工程可能的极限载荷下可有效确保稳定性。

弹簧式QSD性能及切屑根部绝热剪切带实验研究

研究一种弹簧式快速落刀装置的工作性能,用该装置获取切屑根部试样,考察锯齿形切屑绝热剪切带。使用高速相机记录弹簧式快速落刀装置刀杆的运动轨迹,计算刀杆端点初始速度、加速度;分析落刀实验过程中工件转动与刀具进给运动的影响,定性讨论金属变形惯性的影响;在普通车床上对盘状试样进行直角自由切削方式的快速落刀实验,得到锯齿形切屑根部,制成金相标本,研究切削区绝热剪切带。该弹簧式快速落刀装置可替代爆炸式快速落刀装置,能有效地获取一定切削速度、切削层厚度条件下的切屑根部试样。

一种新型模数式伸缩缝位移控制系统

大跨径桥梁通常使用的伸缩缝有两种形式:剪力弹簧式和转轴式。通过对剪力弹簧式、转轴式两种大位移伸缩缝中常用的结构形式优劣的对比,提出了一种新的结构形式:等距变位式伸缩缝。实际运行结果表明:该形式伸缩缝兼具剪力弹簧式结构简单,受力清晰,加工组装难度低,成本低和转轴式伸缩缝缝宽调整能力强的优点。

Effect of imperfect bonding on the dynamic response of a pre-stressed sandwich plate-strip with elastic layers and a piezoelectric core

In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigation is carried out within the framework of the piecewise homogeneous body model by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity.It is assumed that there is a shear-spring-type imperfect contact between the layers,but a complete contact between the plate-strip and the rigid foundation.A mathematical model of the problem is constructed,and the governing equations of motion are solved by employing the finite element method（FEM）.Numerical results illustrating the influence of a change in the value of the shear-spring parameter on the dynamic response of the plate-strip are then presented.