应力释放孔对弛张筛筛板使用寿命和透筛率影响的研究

Study of the effect of stress-relief holes on service life of screenplate and penetration rate of flip-flop screen

针对弛张筛筛板折弯处因在生产中受到交变拉伸-挠曲应力容易发生撕裂的问题,为了降低筛板折弯处应力,提高筛板使用寿命,基于应力释放孔的工程原理,提出在筛板折弯处设置一定数量的应力释放孔,并采用有限元仿真的方式验证筛板折弯处的应力,通过有限元-离散元耦合仿真的方法分析折弯处开孔对透筛率的影响。研究结果表明:该方法可以降低筛板所受应力,使折弯处最大挠曲应力降低了0.43 MPa,最大拉伸应力降低了0.16 MPa,有利于提高筛板使用寿命;且筛板折弯处开孔对颗粒透筛率几乎没有影响。该研究可为筛板结构形式和优化提供有益参考。

The bent parts of the screen plate of the flip-flop screen are liable to become ruptured under the effect of alternate tensile and flexural stresses to which they are subjected during their fabrication process.In order to decrease the stress of the bent parts of the screen plate and prolong its service life,Based on the principle of the engineering concept of having the stress released through opening of holes,it is proposed to open a number of holes on the side of each bent part of the screen.Work is made on a-nalysis of the stress to which each bent part is subjected through finite element simulation,as well as the effect on penetration rate produced by the stress-relief holes,by means of finite element-discrete element coupled simulation.Study result shows that the stressed state of the screen plate is much improved and the maximum flexural and tensile stresses experienced by the bent parts can see a noticeable reduction by 0.43 MPa and 0.16 MPa respectively,and almost no effect is produced on material penetration rate by the presence of the holes.The study result provides some useful reference for the optimization of structural form of screen plate.