蜂巢组织的三维结构模拟

Three-dimensional structural simulation of honeycomb woven structure

为解决蜂巢织物模拟时仿真度不高、经纬纱空间轨迹不准确等问题,提出一种蜂巢织物的模拟方法。将浮长线的拉拢作用与邻近组织点偏移倾向等因素相结合,分析了浮长线内组织点的偏移;在此基础上,建立了组织点偏移的数学模型,提出纱线偏移的算法。为避免偏移后不同纱线间的渗透与穿刺,依照机织物的织造规律设计了纱线的碰撞检测与处理算法;考虑蜂巢织物的凹凸外观,将织物的平纹组织划分为凸起和凹下二部分。研究结果表明:采取偏移算法后的织物模拟效果逼真,更接近实际织物中纱线的空间轨迹;经碰撞检测处理后的纱线一方面减少了渗透,另一方面也突出了织物的凹凸效果;对蜂巢织物平纹部分的划分处理使模拟织物表观的倒金字塔凹槽清晰可见,取得了预期效果。

Objective At present,the simulation of honeycomb fabric does not refelect the reality closely,leading to deviation warp and weft yarns caused by floating lines and other factors,and the unique three-dimensional effect of the honeycomb woven fabrics is not able to be represented.In order to solve the problems,a new simulation method for honeycomb fabrics was proposed.Method Combined with the pull-in effect of floating line and the deviation tendency of adjacent weave points,the deviation of weave points in floating line was analyzed.On this basis,the mathematical model of weave point deviation was established and the algorithm of yarn deviation was put forward.In order to avoid the interference between yarns after offset,the collision detection and processing algorithm of yarns was designed according to the structure of woven fabrics.Considering the concave-convex appearance of honeycomb fabrics,the plain weave of the fabric was divided into two parts,i.e.the convex part and the concave part.Results Starting from the pull-in effect of the floating line,the offset l of the weave points in the floats was analyzed,and the arch height h was calculated.It was learnt that the longer the floats length,the more pronounced the bumpy effect of the fabric.When analyzing the deviation of weave points,the fabric structure was also considered.A mathematical model has been developed where the offset of the interlacing points are affected by a combination of both.Based on the mathematical model,the yarn deviation algorithm was proposed,and the honeycomb structure was simulated by using this algorithm.In the process of deviation,different yarns were bound to collide.According to the geometric cross-section relationship,an algorithm for collision detection in the same system was proposed.Taking the weave points of yarns and the midpoint coordinates between the weave points as the model points,the centerline trajectory of yarns is outlined by spline curves,and the collision treatment of yarns in different systems was avoided by improving the z value of the midpoint coordinates between the weave points.The honeycomb structure was simulated by combining the two collision treatment algorithms.In order to show the gradual transition of concave-convex honeycomb appearance,the plain part of the fabric was divided into two parts,part A the convex and part B the concave.The height of the plain weavewas is analyzed,and its z value was the product of the proportional coefficient p and the height of the floating line in another system,which shows the appearance of the honeycomb fabric in the shape of an inverted cone and pyramid.Conclusion After using the migration algorithm,the simulated honeycomb fabric has been made more realistic and can better reflect the spatial trajectory of warp and weft yarns in the fabric.The yarn deviation algorithm based on the floating line principle and the number of offset interlacements is not only suitable for honeycomb structure,but can also be used for reference in the simulation of special structures such as mesh,through holes and ribs.The traditional collision detection methods are bounding box and ray detection,but the warp and weft system of a woven fabric has its own rules,and the collision algorithm designed in this research greatly reduces the calculation amount.Dividing the plain part of the fabric into two categories is the key to form the appearance of inverted cone and inverted pyramid groove.