论文在分析了现有高速公路避险车道应用现状基础上，提出了采用强阻尼减速作用的泡沫橡胶作为避险车道制动床材料的研究思路，并对此进行了深入研究。 首先，论文从材料的特性和变形出发，通过单轴拉伸、单轴压缩、剪切、紫外线加速耐老化等试验，对初步选定的ρ=160 kg/m³的EPDM（三元乙丙）闭孔泡沫橡胶材料物理、力学性能进行了研究，获得了材料的抗拉强度、泊松比、抗剪强度等材料性能指标，并得出泡沫橡胶用于避险车道的强阻尼减速机理。根据试验结果，得到两点结论：一、采用EPDM泡沫橡胶作为制动床材料，能够在长期强紫外线辐射下保持物理性能的稳定，满足路面材料对环境条件的要求；二、车辆荷载作用下，泡沫橡胶路面的压缩变形大小与减速效果直接相关，变形越大，对失控车辆阻尼减速作用越佳。 随后，论文从室外实车静载试验入手，对不同厚度泡沫橡胶路面的压缩变形进行定量研究。接着，利用小半径轮胎，在室内对轮胎-泡沫橡胶路面接触作用开展试验，研究不同的载荷大小、加载速率和路面厚度条件对泡沫橡胶路面变形的影响。 为进一步研究泡沫橡胶路面在轮胎载荷作用下的力学响应情况，论文利用ABAQUS有限元分析软件，建立了215/70R15、12R22.5型子午线轮胎模型和泡沫橡胶路面模型，对静态压缩时轮胎-路面接触面应力分布、轮胎与路面的变形情况及轮胎自由滚动时滚动阻力、减速度进行了仿真分析，得出了丰富的结果。 最后，论文以试验与仿真结果作为新型避险车道设计的指标，对新型避险车道进行了初步设计。与传统的避险车道相比，新型避险车道能够安全、有效的对失控车辆进行减速，为避险车道的改进及设计提供了参考与依据。 关键词：避险车道，泡沫橡胶，轮胎，强阻尼，滚动阻力，有限元 |
Foam rubber with strong damping is brought forward to apply on highway truck escape ramp based on the present application situation analysis of the traditional truck escape ramp, and some further researches are done as following. Firstly, uniaxial tension, uniaxial compression, simple shear and aging resistance test are done to study the physical and mechanical properties of EPDM foam rubber with closed cell (ρ=160 kg/m³) which is preliminary selected, and tensile strength, Poisson´ ratio and shear strength is obtained. Through uniaxial compression test, the strong damping reduction mechanism of the foam rubber is also obtained. According to test results, two conclusions are got. First, EPDM foam rubber can maintain physical properties stability under long-term strong ultraviolet radiation when used as brake bed material. Second, there is directly relationship between deceleration effect and the compression deformation of foam rubber. The greater the deformation is, the better deceleration effect will be got. Secondly, static load test with real vehicle is taken on different thickness foam rubber pavement, and quantitative research is carried on. Then, tire-foam rubber surface contact tests are done to study the impact of load, load rate and the foam rubber thickness on deformation of foam rubber pavement. For the further study of foam rubber pavement mechanics response under tire load, finite element software-ABAQUS is used to simulate deformation of tire and road, contact stress distribution of tire-road contact area under static compression, rolling resistance and deceleration under tire free rolling condition, in which many results are got. Finally, preliminary design for new kind of truck escape ramp is done according to the experiment and the simulation results. Compared with the traditional truck escape ramp, new truck escape ramp can safely and effectively decelerate the vehicle out of control, which provides reference for design and improvement of truck escape ramp. Keywords: Trucks escape ramp, Foam Rubber, Tire, Strong Damping, Rolling Resistance, Finite Element Method |
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