亚洲毛片网,丝袜美腿二区,亚洲精品高清在线观看,91看国产,国产小视频在线观看,欲罢不能第三季的综艺节目,成人免费一级电影

A structure formed by connecting rods with hinges at both ends. The truss is composed of straight rods and generally has a plane or space structure with triangular members. The truss members mainly bear axial tension or pressure, so that the strength of the material can be fully utilized. When the span is large, the material can be saved compared with the solid web beam, and the weight and can be reduced but increase stiffness. Common trusses shapes are: triangular trusses, trapezoidal trusses, polygonal trusses, hollow trusses, and truss bridges.