针对滤袋弹性圆环的弹力检测由人工经验评价和人工拆卸已检圆环劳动强度大等问题,设计了一种滤袋弹性圆环弹力检测与圆环拆卸一体化装置。首先测试了滤袋弹性圆环约束状态下受径向压力下的弹力和变形量,提出了滤袋弹性圆环弹力检测与圆...针对滤袋弹性圆环的弹力检测由人工经验评价和人工拆卸已检圆环劳动强度大等问题,设计了一种滤袋弹性圆环弹力检测与圆环拆卸一体化装置。首先测试了滤袋弹性圆环约束状态下受径向压力下的弹力和变形量,提出了滤袋弹性圆环弹力检测与圆环拆卸装置原理,其次开展结构设计和样机试制、组装、调试。用本研究开发的装置开展了滤袋弹性圆环弹力检测与圆环拆卸因素影响试验,结果表明拆卸机构的主气缸推压深度、拆卸气缸推压位置、拆卸气缸推力分别为90 mm、b、80 N时能够成功拆卸滤袋弹性圆环。To address issues such as the high labor intensity of manual evaluation and disassembly of the elastic rings used in dust filter bags, we designed elastic force detection and disassembly integration equipment for an elastic ring of the dust filter bag. First, we tested the elasticity and deformation of the elastic rings under radial pressure in a constrained state. We then proposed the working principle of the equipment for elasticity testing and ring disassembly. Subsequently, we conducted structural design, prototype fabrication, assembly, and debugging. Utilizing the equipment developed in this study, we performed experiments to investigate the factors affecting both the elasticity testing of the elastic rings and the disassembly process. The results indicated that the main cylinder’s push depth, push position, and push force of the disassembly cylinder, set at 90 mm, b, and 80 N, respectively, successfully enabled the disassembly of the dust filter bag’s elastic rings.展开更多
The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model...The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional（3D）viscoelastic flow through elliptical ring die for polymer extrusion was investigated.The penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion problem.The discrete elastic viscous split stress（DEVSS）and streamline-upwind PetrovGalerkin（SUPG）technology were used to obtain stable simulation results.Free surface was updated by updating the streamlines which needs less memory space.According to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased markedly.Finally,the numerical simulation of extrudate swell flow for low-density polyethylene（LDPE）melts was investigated and the results agreed well with others’work.These conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape.展开更多
A general method was proposed to study the sound and vibration of a finite cylindrical shell with elastic theory. This method was developed through comprehensive analysis of the uncoupled Helmholtz equation obtained b...A general method was proposed to study the sound and vibration of a finite cylindrical shell with elastic theory. This method was developed through comprehensive analysis of the uncoupled Helmholtz equation obtained by the decomposition of elastic equations and the structure of the solution of a finite cylindrical shell analyzed by thin shell theory. The proposed method is theoretically suitable for arbitrary thickness of the shell and any frequency. Also, the results obtained through the method can be used to determine the range of application of the thin shell theory. Furthermore, the proposed method can deal with the problems limited by the thin shell theory. Additionally, the method can be suitable for several types of complex cylindrical shell such as the ring-stiffened cylindrical shell, damped cylindrical shell, and double cylindrical shell.展开更多
文摘针对滤袋弹性圆环的弹力检测由人工经验评价和人工拆卸已检圆环劳动强度大等问题,设计了一种滤袋弹性圆环弹力检测与圆环拆卸一体化装置。首先测试了滤袋弹性圆环约束状态下受径向压力下的弹力和变形量,提出了滤袋弹性圆环弹力检测与圆环拆卸装置原理,其次开展结构设计和样机试制、组装、调试。用本研究开发的装置开展了滤袋弹性圆环弹力检测与圆环拆卸因素影响试验,结果表明拆卸机构的主气缸推压深度、拆卸气缸推压位置、拆卸气缸推力分别为90 mm、b、80 N时能够成功拆卸滤袋弹性圆环。To address issues such as the high labor intensity of manual evaluation and disassembly of the elastic rings used in dust filter bags, we designed elastic force detection and disassembly integration equipment for an elastic ring of the dust filter bag. First, we tested the elasticity and deformation of the elastic rings under radial pressure in a constrained state. We then proposed the working principle of the equipment for elasticity testing and ring disassembly. Subsequently, we conducted structural design, prototype fabrication, assembly, and debugging. Utilizing the equipment developed in this study, we performed experiments to investigate the factors affecting both the elasticity testing of the elastic rings and the disassembly process. The results indicated that the main cylinder’s push depth, push position, and push force of the disassembly cylinder, set at 90 mm, b, and 80 N, respectively, successfully enabled the disassembly of the dust filter bag’s elastic rings.
基金Supported by the National Science Foundation for Distinguished Young Scholars of China（50425517） the Shandong Province Natural Science Foundation（Y2007F59）
文摘The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional（3D）viscoelastic flow through elliptical ring die for polymer extrusion was investigated.The penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion problem.The discrete elastic viscous split stress（DEVSS）and streamline-upwind PetrovGalerkin（SUPG）technology were used to obtain stable simulation results.Free surface was updated by updating the streamlines which needs less memory space.According to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased markedly.Finally,the numerical simulation of extrudate swell flow for low-density polyethylene（LDPE）melts was investigated and the results agreed well with others’work.These conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape.
基金Supported by the National Natural Science Foundation of China under （Grant No. 40976058）
文摘A general method was proposed to study the sound and vibration of a finite cylindrical shell with elastic theory. This method was developed through comprehensive analysis of the uncoupled Helmholtz equation obtained by the decomposition of elastic equations and the structure of the solution of a finite cylindrical shell analyzed by thin shell theory. The proposed method is theoretically suitable for arbitrary thickness of the shell and any frequency. Also, the results obtained through the method can be used to determine the range of application of the thin shell theory. Furthermore, the proposed method can deal with the problems limited by the thin shell theory. Additionally, the method can be suitable for several types of complex cylindrical shell such as the ring-stiffened cylindrical shell, damped cylindrical shell, and double cylindrical shell.
