极限工况下膜式空气弹簧安全保护设计及力学特性研究

RESEARCH ON SAFETY PROTECTION DESIGN AND MECHANICAL CHARACTERISTIC OF ROLLING LOBE AIR SPRING UNDER EXTREME CONDITION

安全防护设计是结构设计中需考虑的关键问题,进行极限工况下膜式空气弹簧(Rolling Lobe Air Spring,PLAS)的力学特性研究可为开展其安全保护设计奠定重要基础。计及橡胶气囊外径随弹簧高度变化影响,考虑圆弧段半径、直线段内锥角等关键设计参量,建立了具有安全保护设计的膜式空气弹簧力学特性模型。试验结果表明,膜式空气弹簧结构参数最大相对误差为11.9%,极限工况时不同压强下静刚度相对误差均小于11%,承载力最大相对误差均小于6%,证明了所建立RLAS力学特性模型的正确性。进一步提出以力增益、刚度增益作为安全保护设计的量化表征指标,探明了极限工况下关键设计参量对RLAS力学特性、量化表征指标的影响规律。研究结果为设计阶段准确计算RLAS的安全保护能力提供了理论支撑。

Safety protection design is a key problem to be considered in structural design.The study on mechanical characteristics of rolling lobe air spring(RLAS)under the extreme working condition lays an important foundation for its safety protection design.Considering the influence of outer diameter of rubber bellows along with the height of air spring,taking the radius of arc segment and inner cone angle of linear segment as the key design parameters,a novel mechanical model of rolling lobe air spring with safety protection design is established.The experimental results show that the maximum relative error of structural parameters of rolling lobe air spring is 11.9%,the relative error of static stiffness under different pressure in the extreme condition is less than 11%and the maximum relative error of load capacity is less than 6%,which all proves the correctness of mechanical model of RLAS.Force gain and stiffness gain are further proposed as quantitative characterization indexes of safety protection design,and the influence laws of key design parameters on mechanical characteristics and quantitative characterization indexes of rolling lob air spring under extreme condition are explored.The research results provide theoretical support for accurate calculation of safety protection capability of RLAS in the design stage.