圆竹材因其特殊的外形和结构性不适应建筑工程的要求,因而在建筑结构领域内的研究和应用基本上处于空白状态。以我国丰富的毛竹作为结构材料,对其进行大量的材性试验和分析。研究结果表明,经过合理选材,圆竹的基本力学指标高于TC13级针...圆竹材因其特殊的外形和结构性不适应建筑工程的要求,因而在建筑结构领域内的研究和应用基本上处于空白状态。以我国丰富的毛竹作为结构材料,对其进行大量的材性试验和分析。研究结果表明,经过合理选材,圆竹的基本力学指标高于TC13级针叶木材,可以作为结构材料使用。通过设计的几种圆竹构件和结构的金属连接件,基本实现了圆竹构件加工的标准化和施工的预制化。对2个圆竹墙体进行抗侧力试验,圆竹墙体的抗侧向承载能力约为同类型轻型木结构墙体的65%。对3个圆竹屋架进行了静载试验,屋架的极限承载力由变形控制,平均值为12.3 k N。根据试验结果和GB/T 50329—2002《木结构设计规范》,设计和建造了一个约50 m2的圆竹预制房屋示范建筑,验证了圆竹预制房屋技术的可行性和适用性。展开更多
With the increasing requirement for the mechanical vibration and acoustic noise of the permanent magnet synchronous motor(PMSM)drive system,the demand for cogging torque reduction of PMSM has been considerably increas...With the increasing requirement for the mechanical vibration and acoustic noise of the permanent magnet synchronous motor(PMSM)drive system,the demand for cogging torque reduction of PMSM has been considerably increased.To solve the problem of oversized cogging torque of axial flux PMSM,a rotor topology with hybrid permanent magnet is proposed to weaken the cogging torque.Firstly,the expression of the cogging torque of the axial flux motor is derived,and the influence of the pole-arc ratio of the permanent magnet on the cogging torque is analyzed.Secondly,the rotor structure with hybrid permanent magnet is adopted to reduce the cogging torque.According to the analytical analysis,the constraints of the size and pole-arc ratio between the hybrid permanent magnets are obtained,and the two permanent magnets related to the minimum cogging torque are determined.And the analysis results are verified by the finite element simulation.Furthermore,the motor performance with and without the hybrid permanent magnet is compared with each other.Finally,the cogging torque is significantly reduced by adopting a rotor structure with hybrid permanent magnets.展开更多
文摘圆竹材因其特殊的外形和结构性不适应建筑工程的要求,因而在建筑结构领域内的研究和应用基本上处于空白状态。以我国丰富的毛竹作为结构材料,对其进行大量的材性试验和分析。研究结果表明,经过合理选材,圆竹的基本力学指标高于TC13级针叶木材,可以作为结构材料使用。通过设计的几种圆竹构件和结构的金属连接件,基本实现了圆竹构件加工的标准化和施工的预制化。对2个圆竹墙体进行抗侧力试验,圆竹墙体的抗侧向承载能力约为同类型轻型木结构墙体的65%。对3个圆竹屋架进行了静载试验,屋架的极限承载力由变形控制,平均值为12.3 k N。根据试验结果和GB/T 50329—2002《木结构设计规范》,设计和建造了一个约50 m2的圆竹预制房屋示范建筑,验证了圆竹预制房屋技术的可行性和适用性。
基金supported by the Natural Science Foundation of Hubei Province(No.2019 CFB759)。
文摘With the increasing requirement for the mechanical vibration and acoustic noise of the permanent magnet synchronous motor(PMSM)drive system,the demand for cogging torque reduction of PMSM has been considerably increased.To solve the problem of oversized cogging torque of axial flux PMSM,a rotor topology with hybrid permanent magnet is proposed to weaken the cogging torque.Firstly,the expression of the cogging torque of the axial flux motor is derived,and the influence of the pole-arc ratio of the permanent magnet on the cogging torque is analyzed.Secondly,the rotor structure with hybrid permanent magnet is adopted to reduce the cogging torque.According to the analytical analysis,the constraints of the size and pole-arc ratio between the hybrid permanent magnets are obtained,and the two permanent magnets related to the minimum cogging torque are determined.And the analysis results are verified by the finite element simulation.Furthermore,the motor performance with and without the hybrid permanent magnet is compared with each other.Finally,the cogging torque is significantly reduced by adopting a rotor structure with hybrid permanent magnets.
