在采用离散元法分析机械部件与颗粒材料接触作用时,需要建立机械部件(边界)的离散元法分析模型。分析可知,机械部件中与颗粒材料接触作用的零件表面,存在不能用初等解析函数表达的非规则曲面。为此,采用推进波前法(AFT:Advancing Front ...在采用离散元法分析机械部件与颗粒材料接触作用时,需要建立机械部件(边界)的离散元法分析模型。分析可知,机械部件中与颗粒材料接触作用的零件表面,存在不能用初等解析函数表达的非规则曲面。为此,采用推进波前法(AFT:Advancing Front Technique)进行非规则曲面网格划分,把非规则曲面离散成三角形平面片的组合,同时添加运动属性和材料特性参数,由此建立非规则曲面边界的离散元法分析模型。在对PRO/E软件进行二次开发的基础上,研制了非规则曲面边界建模软件。通过实例验证,初步证明了基于AFT边界建模方法和软件的可行性,为复杂结构机械部件工作过程的仿真分析奠定了基础。展开更多
Landslides are a type of natural disaster that can cause substantial harm to humanity.Monitoring and predicting the initiation of potential landslides is critical to avoiding losses due to disasters and economic activ...Landslides are a type of natural disaster that can cause substantial harm to humanity.Monitoring and predicting the initiation of potential landslides is critical to avoiding losses due to disasters and economic activities.The impact of the controlled-source audio-frequency magnetotelluric method on investigating landslide surfaces is assessed through numerical simulations with a finite element approach.A Dirichlet boundary condition is selected to match the truncated boundary,resulting in a remarkable improvement in simulation efficiency.Rederivation of the formulas for a layered medium adept to the controlled-source audiofrequency magnetotelluric method is necessary to determine the electromagnetic field at any location along the truncated boundary.After the reliability evaluation of the new codes,a landslide model with a slide surface is designed,and the characteristics of its electromagnetic field and the apparent resistivity are studied.Instead of the total electromagnetic field,which is strongly infl uenced by topography variation,the apparent resistivity should be used for sliding surface detection.The normalized pure anomalous electromagnetic field may also be employed to quickly assess the detectability of the sliding surface.Overall,this study demonstrates that the controlled-source audio-frequency magnetotelluric method can be employed for investigating landslides,and recommends survey parameters,including configuration,frequency range,and length of survey line in landslide exploration.展开更多
文摘在采用离散元法分析机械部件与颗粒材料接触作用时,需要建立机械部件(边界)的离散元法分析模型。分析可知,机械部件中与颗粒材料接触作用的零件表面,存在不能用初等解析函数表达的非规则曲面。为此,采用推进波前法(AFT:Advancing Front Technique)进行非规则曲面网格划分,把非规则曲面离散成三角形平面片的组合,同时添加运动属性和材料特性参数,由此建立非规则曲面边界的离散元法分析模型。在对PRO/E软件进行二次开发的基础上,研制了非规则曲面边界建模软件。通过实例验证,初步证明了基于AFT边界建模方法和软件的可行性,为复杂结构机械部件工作过程的仿真分析奠定了基础。
基金supported by the Project 42374170,XDA0430101.and 2022YFF0706200.
文摘Landslides are a type of natural disaster that can cause substantial harm to humanity.Monitoring and predicting the initiation of potential landslides is critical to avoiding losses due to disasters and economic activities.The impact of the controlled-source audio-frequency magnetotelluric method on investigating landslide surfaces is assessed through numerical simulations with a finite element approach.A Dirichlet boundary condition is selected to match the truncated boundary,resulting in a remarkable improvement in simulation efficiency.Rederivation of the formulas for a layered medium adept to the controlled-source audiofrequency magnetotelluric method is necessary to determine the electromagnetic field at any location along the truncated boundary.After the reliability evaluation of the new codes,a landslide model with a slide surface is designed,and the characteristics of its electromagnetic field and the apparent resistivity are studied.Instead of the total electromagnetic field,which is strongly infl uenced by topography variation,the apparent resistivity should be used for sliding surface detection.The normalized pure anomalous electromagnetic field may also be employed to quickly assess the detectability of the sliding surface.Overall,this study demonstrates that the controlled-source audio-frequency magnetotelluric method can be employed for investigating landslides,and recommends survey parameters,including configuration,frequency range,and length of survey line in landslide exploration.
