构建了四自由度(4-DOF)人-椅耦合模型,以表征头部之间的不同接触模式,胸背,腰背部和靠背。座头传递比(STHT)用作减振效果的评估指标。该模型的仿真减振比与实验结果接近,证明了模型的有效性。在座椅靠背支撑下,STHT峰值明显降低(P<0.05,T检验)。实验表明,支撑头部(一1,P<0.05,Wilcoxon匹配对符号等级)具有最佳的减振效果(21%),支撑胸部背部(a2,P<0.05)具有降低的效果(11%),并支撑腰部背部(a3,P<0.05)的作用最弱(4%)。当上部躯干与靠背完全接触时,峰值STHT曲线和共振频率与座面接触刚度呈正相关,与接触阻尼呈负相关。为了降低座椅到头部的传递比,提出了在两种环境(周期性和非周期性激励)下选择靠背接触刚度和阻尼的选择方法,即最低的STHT峰值和最低的总能量判断。分别。
Four-degree-of-freedom (4-DOF) human-chair coupling models are constructed to characterize the different contact modes between the head, chest back, waist back and
backrest. The seat-to-head transfer ratio (STHT) is used as an evaluation metric for vibration reduction effectiveness. The simulated vibration reduction ratio of the model is close to the experimental results, which proves the validity of the model. The peak STHT is obviously reduced (P < 0.05, T-test) with seat-
backrest support. The experiments show that supporting the head ( a 1 , P < 0.05, Wilcoxon matched-pairs signed ranks) has the best vibration reduction effect (21%), supporting the chest back ( a 2 , P < 0.05) has a reduced effect (11%), and supporting the waist back ( a 3 , P < 0.05) has the weakest effect (4%). When the upper torso is in full contact with the
backrest, the peak STHT curve and resonance frequency are positively correlated with the contact stiffness of the seat surface and negatively correlated with the contact damping. In order to reduce the seat-to-head transfer ratio, the lowest STHT peak and lowest total energy judgments were proposed as the selection methods for the selection of the contact stiffness and damping of the
backrest in two environments (periodic and non-periodic excitation), respectively.