摘要
目的目前动物骨折常用的锁定骨板内固定技术(Point-contact Reconstruction Compress Locking, PRCL)需要采用多个工具配合手动完成骨板成形,针对该过程中精度不可控、效率低等问题,提出一种弯扭复合成形模具,发展一种局部增量成形金属骨板的方法。方法 PRCL骨板固定治疗中,为了贴合受伤骨骼,治疗前骨板需经过面内弯曲、弯曲以及扭转3类变形。通过调整弯扭复合成形模具的空间位置及模具不同组成部分的相对位置,实现不同区域内不同变形量的面内弯曲、弯曲或扭转。应用数值方法分析验证弯扭复合成形模具及成形方法的适用性,基于DEFORM软件建立工业纯钛TA2骨板局部增量成形过程有限元模型,分析具有两个成形区的TA2骨板局部增量成形特征。结果塑性变形仅发生在复合模具附近,对已变形区无影响,会引起未成形区的刚性位移;骨板长度方向受力小于其宽度和厚度方向受力,面内弯曲需要较大的成形载荷。结论所发展的模具和方法可实现预期的骨板成形,也适用于其他PRCL金属骨板的成形。
The internal fixation technique using PRCL (Point-contact Reconstruction Compress Locking) bone plate is widely used to treat fracture in animal. The paper aims to design a bending-twisting compound die and to develop a new local incremental forming method to solve problems, such as requirement of multi hand-operated tools, uncontrollable forming precision and long processing time in manufacture of bone plate. To match the surface of fractured bone when treating fracture with PRCL bone plate, the bone plate needed undergo in-plane bending, bending or twisting deformations before treatment. The in-plane bending, bending or twisting with different deformation in different local area was implemented by adjusting the spatial position of the compound die and the relative position between forming parts of the compound die. The numerical method was used to analyze and validate the applicability of the developed bending-twisting compound die and local incremental forming method for forming metal bone plate. Based on the DEFORM software, the finite element model of local incremental forming process for pure titanium TA2 was developed, the deformation characterisitics for local incremental forming process of TA2 bone plate with two forming area were analyzed. The plastic deformation only occurred around the compound die, and it had no influence on the deformed area. But it may result in rigid displacement in un-deformed area;the load along the length of bone plate was less than that along the width and thickness of bone plate, and the load required for in-plane bending was greater than that of forming. The desired formation of bone plate can be achieved by the developed new method and compound die. The developed new method and compound die are also suitable for the formation of other PRCL metal bone plates.
作者
刘素平
张大伟
刘炳坤
LIU Su-ping;ZHANG Da-wei;LIU Bing-kun(School of Life Science and Engineering, Northwest Minzu University, Lanzhou 730106, China;School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China)
出处
《精密成形工程》
2019年第4期104-112,共9页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(51675415)
关键词
动物骨折
内固定
局部增量成形
复合模具
数值模拟
fracture in animals
internal fixation
local incremental forming
compound die
numerical simulation
