刚壁气承轴心受压杆件的受力性能分析

Study on load-carrying capacity of inflatable axially compressive member with rigid-outer-wall

为在受压杆件中充分利用材料的抗拉强度,提出一种新形式的杆件——刚壁气承轴心受压杆件,介绍杆件的结构形式,该杆件的主要特点为:杆件的轴心压力完全由内部高压气囊承受,约束刚壁不受压应力,稳定性好,承载力可调节。推导刚壁气承轴心受压杆件的承载力公式,并与薄壁圆管进行比较,表明刚壁气承轴心受压杆件具有很好的承载力,当长细比较大时,优势更加明显。以穹顶和射电望远镜结构为例,探讨刚壁气承轴心受压杆件在超大跨度结构和超高精度结构中的应用前景,结果表明:应用刚壁气承轴心受压杆件可以大幅度地降低结构自重,对于超高精度结构来说,还可通过对杆件充气或放气来主动调节杆件的承载力,随时补偿精度的损失,具有很好的应用前景与现实需求。

In order to make full use of the tensile strength of the axially loaded compressive members, a new type of compressive load-carrying member, i.e., the inflatable axially compressive members with rigid-outer-wall, denoted as IACMR, is proposed. The configuration and working modes of the newly proposed member are introduced in detail. The member has good stability and adjustable load-carrying capacity, and the axially compressive load applied to it is fully carried by the internal high-pressure airbag without resulting in compressive stress in the outer rigid wall. The load-carrying capacity formula of the newly proposed member is derived and compared with that of thin-walled steel tube. The results indicate that the member has enough load-carrying capacity when the slenderness ratio of this member is large. Taking dome structures and radio telescope structures as examples, the proposed members are used. A conclusion is drawn that the total weight of structure can be significantly reduced by using the proposed members. For structures with high surface precision, the load-carrying capacity can be adjusted by inflating or deflating the members to compensate the loss of surface precision. From the view of engineering application, the proposed member has good prospect.