外侧搭接层板的厚度对球形封头边缘应力的影响研究

Research on Influence of Thickness of Outer Overlapping Laminate on Edge Stress of Spherical Head

针对筒体与球形封头的连接处存在应力集中的现象,采用外侧层板厚度总和不变,分别按照等差数列递增、等差数列递减改变外侧板的厚度,研究筒体和球形封头连接处的应力变化。研究发现,按等差数列递增时,薄膜应力M随搭接层板壁厚增大而减小,薄膜应力+弯曲应力随搭接层板壁厚增大而减小。各工况下,模型均满足疲劳分析评定。按等差数列递减时,在5%误差允许的范围内,薄膜应力M随搭接层板壁厚增大没有太大变化,薄膜应力+弯曲应力随搭接层板壁厚减小而增大。在t_(1)=5、6、7 mm时,筒体不满足该疲劳寿命评定。其余工况下,模型满足疲劳分析评定。不能单一增大与球形封头直接搭接层板的厚度,且应尽可能选择市场上使用较广泛厚度的层板。

In view of the phenomenon of stress concentration at the joint between the cylinder and the spherical head,the total thickness of the outer laminates is unchanged,the stress change at the joint between the cylinder and the spherical head was studied by changing the thickness of the outer plates according to the increasing arithmetic progression and decreasing arithmetic progression.Research finds that according to the increasing arithmetic progression,the membrane stress M decreases with the increase of the wall thickness of the overlapping layer plate,while the membrane stress plus bending stress decreases with the increase of the wall thickness of the overlapping layer plate.Under all working conditions,the model meets the fatigue analysis evaluation.When according to the decreasing arithmetic progression,within the allowable range of 5% error,the membrane stress M does not change significantly with the increase of the wall thickness of the overlapping laminate.The membrane stress plus bending stress increases with the decrease of the wall thickness of the overlapping layer plate.When t_(1)=5,6,7 mm,the cylinder does not meet the fatigue life assessment.Under other working conditions,the model meets the fatigue analysis evaluation.Therefore,it is not possible to increase the thickness of the laminate directly overlapped with the spherical head,and the laminate with wider thickness in the market should be selected as much as possible.