基于数值模拟的钛合金颅骨修复体多点成形工艺设计

利用多点成形技术成形个性化钛合金颅骨修复体是一种新的数字化制造方法。文章采用动态显式有限元软件,依据实际成形条件建立有限元模型,对选用不同厚度的钢质垫板以及不同润滑条件下钛合金颅骨修复体的成形过程进行模拟,预测可能出现的破裂和起皱缺陷,分析采用不同工艺时成形缺陷的产生原因,并确定了能够获得良好结果的成形工艺。结果表明,采用有压边的多点成形方式,并使用钢质垫板和油润滑以后,可以抑制破裂和起皱缺陷的发生,得到合格的钛合金颅骨修复体,保证颅骨修复体个性化制造的成形质量。实验结果证明,模拟结果和实际吻合良好。

Technical design of the process of multi-point forming for titanium alloy cranial prosthesis based on numerical simulation

It is a new numerical method which forming customized titanium alloy cranial prosthesis by multi-point forming technology. Established the FEM model according to the real forming condition, simulated forming process of the 3D curved surface of prosthesis when different thickness steel padding and different lubricated condition were used, predicted the possible forming defects-wrinkles and cracks by an explicit finite element software. Analyzed the reason to defects appearing when different forming technology modes were adopted, then adjusted the technical parameters until the simulation was successful. Numerical simulation results show that cracks and wrinkles are suppressed when multi-point forming technology are adopted with blank-holder device under lubricated condition. The customized 3D curved surface of prosthesis can be eligible shaped and the forming quality was guaranteed. Finally, the forming tests were performed and the results coincide with the simulation results quite reasonably.