<p class="MsoNormal" style="text-align:justify;"> <span lang="EN-US">The effects of residual stress on the hydro-elastic vibration of circular diaphragm are theoretically investigated by using the added mass approach. The Kirchhoff theory of plates is used to model the elastic thin circular diaphragm on an aperture of an infinite rigid wall and in contact with a fluid on one side. The fluid is assumed to be incompressible and inviscid and the velocity potential is used to describe its irrotational motion. A non-dimensional tension parameter is defined, and the effects of the tension parameter on the frequency parameters and mode shapes of the diaphragm in the air are presented. The Hankel transform is applied to solve the fluid-diaphragm coupled system; boundary conditions are expressed by integral equations. Finally, the effects of residual stress on the non-dimensional added virtual mass incremental (NAVMI) factors of the diaphragm contact with a fluid on one side are investigated. It is found that the effects of the residual stress cannot be neglected when the edges of the circular diaphragm are clamped. The effects of residual stress for NAVMI factors can be increases 11% when the non-dimensional tension parameter is 1000.</span><span lang="EN-US"><o:p></o:p></span> </p>

Dimensional stability of carding machine has a greater impact on the performance of the Cylinder wallboard. Compared with the thermal stress relief (TSR), the vibratory stress relief (VSR) is a new technology which may eliminate the residual stress in metal components with high efficiency, energy saving, environmental protection and low cost. We have 8 pieces of cylinder wallboard castings with every 4 pieces as a group. It takes 20 minutes to do VSR in one of the groups and 20 hours for TSR in another group. Three identical size accuracy indexes are measured, respectively at intervals of 1 month 2 months after aging treatment. The results show that: the dimensional stability of cylinder wallboard vibration by VSR is better than the one by TSR. Energy consumption and cost-saving is more than 90% without "three wastes" emissions.