Pb-GF挤压包覆间隙的数值计算及实验研究

铅包覆玻璃纤维属于塑性材料包覆脆性材料,包覆条件是建立在玻璃纤维不发生变形的情况下,为此,入丝模芯顶端与挤压模口之间的间隙即包覆间隙的优化选择是成形工艺的关键问题.本文采用上限法对包覆挤压过程建立了数值模型,从能量的角度对包覆挤压过程进行了数值计算,将包覆间隙作为一变量引入功的表达武中,并通过数值计算软件给出了数值解,得出包覆间隙的最佳理论值.通过大量的实验证明了数值计算结果与实验结果基本吻合.运用本文结果可以确定不同规格的复合丝材成形时包覆间隙的大小,指导模具设计和工艺参数确定,具有工程意义.

Theoretical derivation and experimental verification of optimal gap during extrusion of composite wire of lead coated on glass fiber

Clad extrusion for lead-clad glass fiber composites is a new process designed for brittle materials coated by plastic materials, in which the glass fiber can not be deformed. So the coating gap between entry and exit of mould isone of the key processing parameters in the fabrication of composite wire. Based on upper bound method in limit analysis, the process of coating extrusion has been derived in detail and the costing gap is introduced into the final expression of power. By means of mathematical software, the numerical solution of optimal gap to the different processing parameters has bee obtained and the result is according with the experiment. The present analysis not only can be extended to determine the optimal gap for the extrusion of different composite wire but also is useful for the designing of the die and the firming of processing parameter.