TB/T 3549.1—2019《机车车辆强度设计及试验鉴定规范转向架第1部分:转向架构架》给出了扭曲载荷的定义,但未明确转向架构架在扭曲载荷条件下开展静态试验和疲劳试验的测试方法。依据转向架构架实验室测试条件和JIS E 4207—2019《铁路...TB/T 3549.1—2019《机车车辆强度设计及试验鉴定规范转向架第1部分:转向架构架》给出了扭曲载荷的定义,但未明确转向架构架在扭曲载荷条件下开展静态试验和疲劳试验的测试方法。依据转向架构架实验室测试条件和JIS E 4207—2019《铁路车辆转向架转向架构架设计通则》,提出一种无一系弹簧条件下测试转向架构架刚度,来完成扭曲载荷试验的方法。详细论述转向架构架扭曲载荷与变形量关系、扭曲刚度测试原理,并对比西南交通大学和实验室扭曲刚度测试方法。有限元软件分析计算结果表明,2种测试方法的误差都控制在6%之内,采用实验室扭曲刚度测试方法,开展加载扭曲载荷试验,用以评估转向架构架结构强度更安全。展开更多
Intervertebral disc flexibility is influenced by lifestyle, loading history, trauma, preexisting conditions, age and degeneration. With regard to degeneration, intervertebral discs become less flexible and stiffer. In...Intervertebral disc flexibility is influenced by lifestyle, loading history, trauma, preexisting conditions, age and degeneration. With regard to degeneration, intervertebral discs become less flexible and stiffer. In this study, a testing protocol using bending and torsion loading was developed to gain the flexibility curves and stiffness often cadaveric lumbar discs. Measurements of rotation in the sagittal plane （flexion-extension）, coronal plane （right-lefl lateral bending） and transverse plane （torsion） due to a 5 N-m load are reported. Results show that overall normal discs are more flexible and behave in a nonlinear fashion. The testing results were used in a develop t＇mite element model of an intervertebral disc to investigate the stresses and strains in the disc components： annulus fibrosus and nucleus pulposus with regard to degeneration. Simulation of bending and torsion loadings show large strains in the annulus and nucleus from a normal disc, in contrast higher stresses develop in the annulus from a degenerated disc. The proposed methodology is novel, versatile, functional and economic with implications in bioengineering, medical sciences and the clinical field.展开更多
文摘TB/T 3549.1—2019《机车车辆强度设计及试验鉴定规范转向架第1部分:转向架构架》给出了扭曲载荷的定义,但未明确转向架构架在扭曲载荷条件下开展静态试验和疲劳试验的测试方法。依据转向架构架实验室测试条件和JIS E 4207—2019《铁路车辆转向架转向架构架设计通则》,提出一种无一系弹簧条件下测试转向架构架刚度,来完成扭曲载荷试验的方法。详细论述转向架构架扭曲载荷与变形量关系、扭曲刚度测试原理,并对比西南交通大学和实验室扭曲刚度测试方法。有限元软件分析计算结果表明,2种测试方法的误差都控制在6%之内,采用实验室扭曲刚度测试方法,开展加载扭曲载荷试验,用以评估转向架构架结构强度更安全。
文摘Intervertebral disc flexibility is influenced by lifestyle, loading history, trauma, preexisting conditions, age and degeneration. With regard to degeneration, intervertebral discs become less flexible and stiffer. In this study, a testing protocol using bending and torsion loading was developed to gain the flexibility curves and stiffness often cadaveric lumbar discs. Measurements of rotation in the sagittal plane （flexion-extension）, coronal plane （right-lefl lateral bending） and transverse plane （torsion） due to a 5 N-m load are reported. Results show that overall normal discs are more flexible and behave in a nonlinear fashion. The testing results were used in a develop t＇mite element model of an intervertebral disc to investigate the stresses and strains in the disc components： annulus fibrosus and nucleus pulposus with regard to degeneration. Simulation of bending and torsion loadings show large strains in the annulus and nucleus from a normal disc, in contrast higher stresses develop in the annulus from a degenerated disc. The proposed methodology is novel, versatile, functional and economic with implications in bioengineering, medical sciences and the clinical field.
