基于薄层单元模型的弹体与引信系统螺纹连接参数确定方法

螺纹连接是侵彻弹体与引信体连接的主要形式之一，直接影响着弹体与引信系统振动响应特性。针对现有数值仿真手段难以准确表征螺纹连接的问题，提出用薄层单元模拟螺纹连接的有效方案，结合理论与试验研究建立薄层单元材料参数的确定方法。基于螺纹连接弹性模型与薄层单元理论推导出薄层单元的材料参数；将薄层单元材料参数传递到有限元模型中进行建模，通过螺纹管以及弹体与引信系统模态试验对薄层单元模型的计算结果进行验证。结果表明：与不同螺距及不同旋合长度螺纹管模态试验结果比较，薄层单元模型计算误差最大为5.11%；与节点融合建模方式比较，弹体与引信系统采用薄层单元建模方式进行计算后，前3阶模态频率最大误差从17.72%下降到2.54%.

The Method for Determining the Threaded Connection Parameters of Projectile-fuze System Based on Thin-layer Element Model

Threaded connection is one of the main connection modes of projectile body and fuze body, which affects the vibration response characteristics of projectile-fuze system directly. For the problem that the existing numerical simulation methods are difficult to characterize the threaded connection accurately, a thin-layer element method is peoposed to simulate the threaded connection, and a determination method for the material parameters of thin-layer element is established through theoretical and experimental research. The material parameters of thin-layer element are determined based on the elastic model of threaded connection and thin-layer element theory.The determined material parameters of thin-layer element are applied to the finite element model. The calculation accuracy of thin-layer element model is verified by the modal test of threaded tube and projectile-fuze system. Compared with the modal test results of threaded pipes with different pitch and thread length, the maximum calculated error of the thin-layer element model is 5.11%. Moreover, compared with the nodes fusion method, the maximum error of the first third-order modal frequency decreases from 17.72% to 2.54% after using thin-layer element method for the projectile-fuze system.