The distribution of shear stress on the cross-section of plastic metal solid circular shaft under pure torsion yielding, the applicability of complete plastic model assumption and the shear stress formula were researc...The distribution of shear stress on the cross-section of plastic metal solid circular shaft under pure torsion yielding, the applicability of complete plastic model assumption and the shear stress formula were researched. Based on the shear stress formula of circular shaft under pure torsion in elastic stage, the formula of torque in elastic stage and the definition of yield, it is obtained that the yielding stage of plastic metal shaft under pure torsion is only a surface phenomenon of torque-torsion angle relationship, and the distribution of shear stress is essentially different from that of tensile stress when yielding under uniaxial tension. The pure torsion platform-torsion angle and the shape of torque-torsion angle curve cannot change the distribution of shear stress on the shaft cross-section. The distribution of shear stress is still linear with the maximum shear stress ts. The complete plasticity model assumption is not in accordance with the actual situation of shaft under torsion. The experimental strength data of nine plastic metals are consistent with the calculated results of the new limiting strain energy strength theory （LSEST）. The traditional yield stress formula for plastic shaft under torsion is reasonable. The shear stress formula based on the plane assumption in material mechanics is applicable for all loaded stages of torsion shaft.展开更多
基于英国克拉克森研究公司和全球主要船级社的网站数据,根据手持订单量和交付与完工情况对全球汽车卡车运输船(Pure Car and Truck Carrier,PCTC)进行市场分析,对全球PCTC平均关键建造周期进行对标分析,查找国内造船企业与国外造船企业...基于英国克拉克森研究公司和全球主要船级社的网站数据,根据手持订单量和交付与完工情况对全球汽车卡车运输船(Pure Car and Truck Carrier,PCTC)进行市场分析,对全球PCTC平均关键建造周期进行对标分析,查找国内造船企业与国外造船企业的差距,为我国造船企业缩短PCTC建造周期提供改进目标。展开更多
Objective: To compare the difference of self-concept between children of complete and divorced family. Methods: 42 subjects in divorced family and 45 controls were tested by Piers-Harris Self-concept Scale for Childre...Objective: To compare the difference of self-concept between children of complete and divorced family. Methods: 42 subjects in divorced family and 45 controls were tested by Piers-Harris Self-concept Scale for Children. Rusults: The students in divorced family reported significantly lower scores on self-concept than the controls on behavior,anxiety, gregariousness, satisfaction and total score. Conclusion: The self-concept of divorced family students is lower than that of the control group.展开更多
文摘The distribution of shear stress on the cross-section of plastic metal solid circular shaft under pure torsion yielding, the applicability of complete plastic model assumption and the shear stress formula were researched. Based on the shear stress formula of circular shaft under pure torsion in elastic stage, the formula of torque in elastic stage and the definition of yield, it is obtained that the yielding stage of plastic metal shaft under pure torsion is only a surface phenomenon of torque-torsion angle relationship, and the distribution of shear stress is essentially different from that of tensile stress when yielding under uniaxial tension. The pure torsion platform-torsion angle and the shape of torque-torsion angle curve cannot change the distribution of shear stress on the shaft cross-section. The distribution of shear stress is still linear with the maximum shear stress ts. The complete plasticity model assumption is not in accordance with the actual situation of shaft under torsion. The experimental strength data of nine plastic metals are consistent with the calculated results of the new limiting strain energy strength theory （LSEST）. The traditional yield stress formula for plastic shaft under torsion is reasonable. The shear stress formula based on the plane assumption in material mechanics is applicable for all loaded stages of torsion shaft.
文摘基于英国克拉克森研究公司和全球主要船级社的网站数据,根据手持订单量和交付与完工情况对全球汽车卡车运输船(Pure Car and Truck Carrier,PCTC)进行市场分析,对全球PCTC平均关键建造周期进行对标分析,查找国内造船企业与国外造船企业的差距,为我国造船企业缩短PCTC建造周期提供改进目标。
文摘Objective: To compare the difference of self-concept between children of complete and divorced family. Methods: 42 subjects in divorced family and 45 controls were tested by Piers-Harris Self-concept Scale for Children. Rusults: The students in divorced family reported significantly lower scores on self-concept than the controls on behavior,anxiety, gregariousness, satisfaction and total score. Conclusion: The self-concept of divorced family students is lower than that of the control group.
