针对菲律宾蛤仔等埋栖贝类采收作业时底质颗粒间缺乏准确的接触参数,该研究以辽宁丹东大鹿岛菲律宾蛤仔养殖区浅海底质为研究对象,选取EDEM中Hertz-Mindlin with JKR接触模型,对底质颗粒间接触参数进行标定。通过物理试验测定了浅海底...针对菲律宾蛤仔等埋栖贝类采收作业时底质颗粒间缺乏准确的接触参数,该研究以辽宁丹东大鹿岛菲律宾蛤仔养殖区浅海底质为研究对象,选取EDEM中Hertz-Mindlin with JKR接触模型,对底质颗粒间接触参数进行标定。通过物理试验测定了浅海底质含水率、容重、内摩擦角、粘聚力和泊松比。基于漏斗法测定了浅海底质堆积角,确定了需要标定接触参数的范围为:JKR表面能4.50~18.00 J/m^(2)、碰撞恢复系数0.35~0.75、静摩擦系数0.20~1.04、滚动摩擦系数0.10~0.20。通过Design-Expert软件的优化模块对模型寻优得到JKR表面能、碰撞恢复系数、静摩擦系数、滚动摩擦系数分别为10.96 J/m^(2)、0.37、0.63、0.10,在该最优解下仿真试验所得堆积角为49.83°,与物理试验所得的堆积角(51.00°)相对误差为2.29%。通过旋切试验对底质间接触参数进行验证,在物理试验与仿真试验中,旋切机构刀轴扭矩相对误差为7.76%,相对误差较小,结果表明标定的参数准确可靠,可为后续研究浅海底质-蛤仔-采收机构互作机制提供重要参考。展开更多
Rock bolts are widely used in rock engineering projects to improve the shear capacity of the jointed rock mass.The bolt inclination angle with respect to the shear plane has a remarkable influence on the bolting perfo...Rock bolts are widely used in rock engineering projects to improve the shear capacity of the jointed rock mass.The bolt inclination angle with respect to the shear plane has a remarkable influence on the bolting performance.In this study,a new artificial molding method based on 3D scanning and printing technology was first proposed to prepare bolted joints with an inclined bolt.Then,the effects of the bolt inclination angle and boundary conditions on the shear behavior and failure characteristic of bolted joints were addressed by conducting direct shear tests under both CNL and CNS conditions.Results indicated that rock bolt could significantly improve the shear behavior of rock joints,especially in the post-yield deformation region.With the increase of bolt inclination angle,both the maximum shear stress and the maximum friction coefficient increased first and then decreased,while the maximum normal displacement decreased monotonously.Compared with CNL conditions,the maximum shear stress was larger,whereas the maximum normal displacement and friction coefficient were smaller under the CNS conditions.Furthermore,more asperity damage was observed under the CNS conditions due to the increased normal stress on the shear plane.展开更多
文摘针对菲律宾蛤仔等埋栖贝类采收作业时底质颗粒间缺乏准确的接触参数,该研究以辽宁丹东大鹿岛菲律宾蛤仔养殖区浅海底质为研究对象,选取EDEM中Hertz-Mindlin with JKR接触模型,对底质颗粒间接触参数进行标定。通过物理试验测定了浅海底质含水率、容重、内摩擦角、粘聚力和泊松比。基于漏斗法测定了浅海底质堆积角,确定了需要标定接触参数的范围为:JKR表面能4.50~18.00 J/m^(2)、碰撞恢复系数0.35~0.75、静摩擦系数0.20~1.04、滚动摩擦系数0.10~0.20。通过Design-Expert软件的优化模块对模型寻优得到JKR表面能、碰撞恢复系数、静摩擦系数、滚动摩擦系数分别为10.96 J/m^(2)、0.37、0.63、0.10,在该最优解下仿真试验所得堆积角为49.83°,与物理试验所得的堆积角(51.00°)相对误差为2.29%。通过旋切试验对底质间接触参数进行验证,在物理试验与仿真试验中,旋切机构刀轴扭矩相对误差为7.76%,相对误差较小,结果表明标定的参数准确可靠,可为后续研究浅海底质-蛤仔-采收机构互作机制提供重要参考。
基金Project(U1865203)supported by the Key Projects of the Yalong River Joint Fund of the National Natural Science Foundation of ChinaProject(51279201)supported by the National Natural Science Foundation of ChinaProjects(2019YFC0605103,2019YFC0605100)supported by the National Key R&D Program of China。
文摘Rock bolts are widely used in rock engineering projects to improve the shear capacity of the jointed rock mass.The bolt inclination angle with respect to the shear plane has a remarkable influence on the bolting performance.In this study,a new artificial molding method based on 3D scanning and printing technology was first proposed to prepare bolted joints with an inclined bolt.Then,the effects of the bolt inclination angle and boundary conditions on the shear behavior and failure characteristic of bolted joints were addressed by conducting direct shear tests under both CNL and CNS conditions.Results indicated that rock bolt could significantly improve the shear behavior of rock joints,especially in the post-yield deformation region.With the increase of bolt inclination angle,both the maximum shear stress and the maximum friction coefficient increased first and then decreased,while the maximum normal displacement decreased monotonously.Compared with CNL conditions,the maximum shear stress was larger,whereas the maximum normal displacement and friction coefficient were smaller under the CNS conditions.Furthermore,more asperity damage was observed under the CNS conditions due to the increased normal stress on the shear plane.
