Delaminations at the free edge of a composite laminate

The concept of a fracture process zone where damage takes place is used to analyse the delaminations at the free edges of angle ply laminates under uniaxial tension. The use of a fracture process zone removes the singularity in the interlaminar stresses and enables the initiation and growth of delaminations to be modelled for a perfect laminate without any assumed prior defects. Two different models for the stress displacement relationship in the fracture process zone are examined: a constant stress up to critical displacement and a linear relationship. Finite element analysis shows that there is little difference in the predictions obtained from the two models. An approximate analysis is presented for the constant stress stress-displacement model which is shown to agree with a finite element solution and experimental data. Hence it is argued that the approximate method using a constant stress model for the fracture process zone is sufficient for accurate prediction of delaminations.     

在内层胶中提高合成橡胶用量降低含胶率的研究

将内层胶配方中合成橡胶用量由原来的30份提高到40份，通过改变炭黑的品种、添加5份白炭黑等方法降低原生产配方的含胶率。试验结果表明，通过配方调整，试验胶料的工艺性能、物理性能和实际使用性能与原配方生产的内层胶接近。     

骨架材料对全钢载重子午线轮胎性能的影响

讨论骨架材料的规格、结构分布及工艺控制对全钢载重子午线轮胎性能的影响。胎体帘布采用带有外缠丝的 3 + 9+ 15× 0 2 2 + 0 15规格钢丝、胎体帘线密度在 45 0～ 65 0根·m- 1 范围内 (帘线直径大于 1 2mm)以及胎体反包端点在成品外轮廓曲线的第 2或 3条装配线上等措施均有利于保证胎体强度 ;合理设计带束层结构 ,端点与胎侧肩部花纹距离取 10mm左右有利于消除应力过度集中 ;采用钢丝增强带有利于提高胎圈刚性。     

高层级轮胎各层帘布裁断角度的计算方法

提出一种新的确定高层级轮胎内外各层帘布裁断角度的方法。根据各层帘布在成品胎内部的材料分布图和在成型机头上的材料分布图，计算该层所在的机头宽度，比较计算的机头宽度和实际的机头宽度，通过调整帘布裁断角度使两者近似相等。以此确定各层帘布的裁断角度，达到内外层帘线均匀伸张的目的。     

混合炭黑TST-103在轮胎内层帘布胶中的应用

研究了混合炭黑TST-103在轮胎内层帘布胶中的应用。小配合和车间大料及成品轮胎试验表明，使用8份混合炭黑TST-103，内层帘布胶的工艺性能、物理性能及实际使用性能均与原内层帘布胶相近，而每千克胶料成本降低了0．33元。     

国产HMMM在胎体帘布胶和带束层胶中的应用

研究国产六甲氧基甲基蜜胺(HMMM)替代进口HMMM在全钢载重子午线轮胎胎体帘布胶和带束层胶中的应用.结果表明,使用国产HMMM的胎体帘布胶和带束层胶的物理性能均与使用进口HMMM的胶料相当,且其与钢丝帘线的粘合性能较好,成品轮胎的耐久性能相差不大;用国产HMMM替代进口HMMM可以大幅度降低原材料成本.     

复合材料尖削结构同级优化方法研究及ISIGHT实现

现有复合材料优化方法在进行尖削结构优化时,设计变量多而且难以保证纤维的连续性,文章提出了一种基于尖削结构模型的复合材料的同级优化方法。通过引入了铺层组、铺层组厚度、铺层组铺层顺序和铺层组距离变量等参数,在不影响优化结果的同时能有效的减少设计变量个数,并保证纤维的连续性。文章借助商业软件ISIGHT实现了该同级优化方法,采用某层合板优化问题验证了该方法的有效性。     

First ply failure study of thin composite conoidal shells subjected to uniformly distributed load

The civil engineers often need to cover large column free open spaces with thin shell structures. The doubly curved shells are characteristically stiff and the ruled surfaces are easy to fabricate. The aesthetically pleasing conoidal shells satisfy both these criteria and are preferred by structural engineers. The engineers now look out for strong but lightweight materials and as a result the laminated composites have evolved. The first ply failure is very important issue for laminated composites. Such studies for plates are reported but similar work on thin shells is very scanty. This paper is aimed to fulfill this lacuna.     

用MasterCAM加工双金属材料链轮硬齿表面

运用MasterCAM软件对双金属材料链轮硬齿表面进行曲面三维造型,编程,并对链轮双金属材料硬齿表面进行曲面合理工艺设计,加工出了符合图纸要求的产品零件。阐述了MasterCAM软件在加工实例产品时编程的基本步骤,重点突出了其加工工艺和加工参数等关键问题。     

高强型高模低收缩涤纶工业长丝的研发

介绍高强型高模量低收缩（HMLS）涤纶工业长丝的生产工艺,通过调整和优化工艺,提高聚酯切片的特性粘度,改善分子结构,生产出了二代和三代HMLS涤纶工业长丝。研究了HMLS涤纶工业长丝在高温受热条件下物理性能的变化。与一代HMLS涤纶工业长丝相比,三代HMLS涤纶工业长丝的耐热性能提高,热强损失降低。