考虑塑性屈服的井下弹道式煤矸分离理论研究

发布时间：2018-03-12 23:35

本文选题：初始屈服点　切入点：Drucker-Prager准则　出处：《固体力学学报》2017年05期 　论文类型：期刊论文

【摘要】：为完善井下弹道式煤矸分离方法的理论体系,对煤和矸石碰撞反弹过程中的弹塑性行为进行研究.以Hertz接触理论为基础,结合Drucker-Prager准则确定了煤和矸石碰撞过程中初始屈服点相对位置的表达式,指出该位置与泊松比近似呈线性关系,并得到初始屈服时相对变形量、接触力和相对速度的数学模型.基于线性强化弹塑性模型,得到接触力与变形量的函数关系,并依据能量守恒定律,确定碰撞分离时刻的相对速度,进而得到反弹距离的理论模型.在单颗粒冲撞实验台上对煤和矸石进行碰撞反弹试验,试验表明:反弹距离随初始速度的增加基本呈增大趋势,当初始速度较小、煤和矸石破碎较少时,采用材料参数平均值计算得到的反弹距离理论解与试验平均值的一致性较好,当煤和矸石有破碎产生时,由于能量的损失,试验平均值小于理论解.
[Abstract]:In order to perfect the theoretical system of ballistic coal and gangue separation method, the elastoplastic behavior of coal and gangue during the collision and rebound process was studied. Based on the Hertz contact theory, the elastoplastic behavior of coal and gangue was studied. Based on the Drucker-Prager criterion, the expression of the relative position of the initial yield point in the process of coal and gangue collision is determined. It is pointed out that this position has a linear relationship with Poisson's ratio, and the relative deformation of the initial yield is obtained. Based on the linear enhanced elastoplastic model, the functional relationship between contact force and deformation is obtained, and the relative velocity at the time of collision separation is determined according to the law of conservation of energy. Then the theoretical model of the rebound distance is obtained. The impact rebound test of coal and gangue is carried out on a single particle collision test bench. The results show that the rebound distance increases with the increase of the initial velocity, and when the initial velocity is small, When coal and gangue are broken less, the theoretical solution of rebound distance calculated by the average material parameter is in good agreement with the experimental average. When coal and gangue are broken, the average value of test is smaller than the theoretical solution because of the loss of energy.
【作者单位】：河南理工大学机械与动力工程学院;中国矿业大学机电学院;
【基金】：国家自然科学基金项目(51404096)资助
【分类号】：O344.1

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