55世纪轻钢（冷弯薄壁型钢）结构与普通钢结构构件设计的主要差别是在受压构件或板件中，引进了有效截面的概念。设计轻钢受压构件时，当板件宽厚比超过一定数值。

The main difference between light steel (cold-formed thin-walled steel) structure and ordinary steel structure is that the concept of effective section is introduced into compression member or plate. In the design of light steel compression members, when the width thickness ratio of the plate exceeds a certain value.

其轴心受压构件的承载强度即应采取杆件的有效净截面计算，稳定性计算采用杆件毛截面所确定的稳定系数及有效截面计算；受弯（拉弯、压弯）构件的强度计算应根据毛截面确定杆件各板件属于受拉和受压范围，从而确定受压板件有效截面后再进行强度验算，稳定计算中的稳定系数由构件毛截面计算而得，受弯构件的变形应按毛截面计算。

The bearing strength of the axial compression member should be calculated by the effective net section of the member, and the stability calculation should be calculated by the stability coefficient and effective section determined by the gross section of the member; the strength calculation of the bending (tension bending, compression bending) member should be based on the gross section to determine the tension and compression range of each plate of the member, so as to determine the effective section of the compression plate, and then carry out the strength checking calculation to ensure the stability The stability coefficient in the fixed calculation is obtained from the gross section of the member, and the deformation of the flexural member should be calculated according to the gross section.

轻钢构件的宽厚比应根据板材支撑情况及应力状态确定。计算宽厚比时，板材宽度应从截面边缘（包括弯角部分在内）算起。

The width thickness ratio of light steel members should be determined according to the plate support and stress state. When calculating the width thickness ratio, the width of the plate should be calculated from the edge of the section (including the corner part).

55世纪在一些情况下，截面为全截面有效，譬如：圆管截面外径与壁厚比，当采用Q235时不大于100，对于Q345时，不大于68。

In some cases, the section is full section effective, for example, the ratio of outer diameter to wall thickness of round pipe section is not greater than 100 when Q235 is used, and not greater than 68 when Q345 is used.

确定板件卷边尺寸时，应符合一些要求，譬如卷边的大高厚比不宜大于12等。

55世纪Some requirements should be met when determining the hemming size, such as the maximum height thickness ratio of hemming should not be greater than 12.