Structural Materials: Steel, Metal, New Steel, Steel structure designing, analyzing and drawing software.

结构建材：钢铁、各种金属、钢结构新产品；钢结构设计、分析、绘图软件。

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However, the main structure of plastic flexible packaging materials are plastic polymers, has some permeability to gas, and therefore can not fully replace the metal and glass packaging.

然而塑料软包装材料主体结构是塑料聚合物，对气体有一定的渗透性，因此并不能完全代替金属、玻璃包装。

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Fatigue failure of metal structural component is a common form of structure collapse, so improving fatigue behavior of metal materials is very important for their usage.

金属构件的疲劳失效是一种常见的结构破坏形式，改善金属材料的疲劳性能对其使用性能的提高有重要意义。

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