利用电磁力随电磁场强度变化而改变的原理,设计电磁支撑与机械支撑并联的试验装置,实现机械系统支撑刚度参数随电磁场强度的变化.通过对试验装置数学模型的研究和线性化分析,给出了通过控制电流的随机改变实现机械系统支撑刚度参数随机变化的四个设计准则.线性化准则可保证机械系统支撑刚度的线性特性;线性随机准则能确保支撑刚度参数与随机控制电流间的线性关系;随机分量显著准则使得支撑刚度具有明显的随机特征,便于试验研究;综合刚度为正的设计准则,能够保证试验系统的稳定性.根据这些设计准则,制成了具有随机刚度支撑参数的模拟试验装置.试验表明,使用该试验装置可以较好地实现支撑刚度参数的随机模拟.
Based on the principle that electromagnetic force varies with electromagnetic field,a test device with parallel electromagnetic and mechanical support elements was designed to realize the varying of the system support stiffness with the electromagnetic field strength.By studying and linearizing the mathematical model of this simulation test device,four design rules were given,making sure that the system support stiffness parameter could be randomly controlled by the controllable random electric current.The linearized rule guarantees the linearity of the system support stiffness;the linear random rule engenders the linear relationship between the support stiffness parameter and the controllable random electric current;the rule of significant random stiffness weight brings about obvious randomness of the system support stiffness,and satisfies the demand of testing;finally the rule of the positive system total stiffness ensures the stability of the simulation test device.Consequently,the simulation test device of random stiffness parameter has been constructed according to these four rules.The test results show that the simulation test device can well simulate the random stiffness parameter.