论文部分内容阅读
十多年来,装卸桥在我国林业系统的贮木场中已得到比较广泛的使用,并在使用中不断地发展及完善。但是也出现了一些问题。现就主桁架下弦杆变形问题作如下分析:在桥吊的结构形式上大多数属于单梁桁架结构。主桁架为三角形截面,小车与驾驶室沿下弦杆行驶。若下弦杆选用槽钢,运行一段时间后,下弦杆可能出现变形。一旦维修不及时,就会严重地威胁着生产的安全。在桥吊设计过程中,一般首先用截面法计算桁架杆件最大
For more than a decade, the loading and unloading bridge has been widely used in the lumberyard of forestry system in our country and has been continuously developed and improved in use. However, some problems have also arisen. Now the main truss under the chord deformation problems are analyzed as follows: Most of the structure of the bridge crane belongs to the single-girder truss structure. The main truss is triangular in cross section, with the car and cab running along the chord. If the lower chord selection channel, after running for a period of time, the lower chord may be deformed. Once the maintenance is not timely, it will seriously threaten the safety of production. In the bridge crane design process, generally the first method to calculate the maximum cross-section truss member