It is prerequisite to measure the three-dimensional braided composite materials preform s technical parameters in the process of its design and production.

在三维编织复合材料预制件的研制和生产过程中，需要测量和分析材料的工艺参数。

The composites were observed by light microscope. The combination quality of matrix between composite layers is deteriorated when density of preform is increased.

通过光学显微镜对复合材料组织进行研究,发现随着Ti-C体系预制块致密度的提高(50%～65%),复合材料中过渡层质量下降。

The proposed FEM preform optimization method is very effective and overcomes abuse of experience design.

所提出的有限元模拟预成形优化方法十分有效,克服了以往凭经验设计的弊端。

And Erbium-doped fiber preform is fabricated using this method.

并利用这种方法实际制作了掺铒光纤预制棒。

It is prerequisite to measure the three-dimensional braided composite materials preform s technical parameters in the process of its design and production.

在三维编织复合材料预制件的研制和生产过程中，需要测量和分析材料的工艺参数。

However, there are still many difficulties in mass production of qualified preform of paper-based friction material using manual sheet-making apparatus. So a semiautomatic sheet-making apparatus was designed to make an improvement.

借鉴于造纸工艺的碳纤维增强纸基摩擦材料预制体成型工艺——“抄片”，成为保证预制体增强纤维、摩擦性能调节剂和填料在预制体中均匀分布的重要一环。