| 摘要: |
| 火箭橇系统的服役工况条件直接导致火箭橇滑块磨损，而滑块的磨损严重威胁着火箭橇系统的可靠运行和长寿命服役安全，更是制约火箭橇系统发展和应用的主要技术瓶颈。因束缚于极端服役工况条件和高昂的试验成本，以及仅通过二维模型或只考虑局部碰撞变形的模拟仿真，尚且未能克服这一问题。根据 Archard 磨损理论、非线性自适应几何更新和弹塑性变形等有限元分析方法及表面织构技术，建立由 0Cr18Ni9Ti 不锈钢滑块和 U71Mn 钢轨钢滑轨组成的有限元三维磨损模型，并分别对火箭橇滑块光滑表面、沟槽型织构化表面进行磨损仿真，揭示滑块磨损过程中接触面磨损、Von-mises 等效应力以及接触压力等接触特征的变化。结果表明：沟槽型织构能够显著影响滑块磨损，织构密度增加促进了接触面均匀磨损，使得应力分布均匀、梯度变化平稳，缓解了应力集中，避免了长时间的剧烈磨损；接触压力也随织构密度的增加而增加，使得接触面与目标面接触紧密、间隙更小，可有效避免磨粒或磨屑引起的三体磨损。有限元模拟表明，通过恰当表面设计获得沟槽型表面织构能够显著影响磨损，也可为实现兼具减摩抗磨性与结构可设计性于一体的火箭橇滑块提供技术参考和理论支撑。 |
| 关键词: 火箭橇滑块 有限元模拟 磨损 沟槽型表面织构 |
| DOI：10.11933/j.issn.1007?9289.20221214003 |
| 分类号:V219 |
| 基金项目:航空科学基金基金（20200029029001）；山西省科技合作交流专项（202204041101021）；“两机”专项（j2019-IV-0004-0071）；陕西省自然科学基础研究计划（2022JM-251）资助项目 |
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| Finite Element Simulation of Wear Behavior of Groove-textured Rocket Sled Slider |
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YAN Kai1, LIN Naiming1, WANG Zhenxia1, WANG Weihua2, ZENG Qunfeng3, WU Yucheng4
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1.College of Material Science and Engineering, Taiyuan University of Technology,Taiyuan 030024 , China;2.Aviation Key Laboratory of Science and Technology on Life-support Technology,Aerospace Life-Support Industries, Ltd., Xiangyang 441003 , China;3.School of Mechanical Engineering, Xi’ an Jiaotong University, Xi’ an 710049 , China;4.National and Local Joint Engineering Research Center for Nonferrous Metals and Processing,Hefei University of Technology, Hefei 230009 , China
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| Abstract: |
| A rocket sled system is a piece of dynamic test equipment driven by a rocket engine on a dedicated track at high forward speeds, for the purposes of collecting test data. Wear is a direct consequence of using the rocket sled system that is serviced under certain working conditions. It has been confirmed that the wear of the slider of the rocket sled system under high-speed and heavy-load conditions seriously threatens the reliable operation and service safety of the rocket sled during operation. The wear damage of rocket sled slider wear is inevitable, and has been considered as a technical bottleneck that restricts the development and application of the rocket sled system. The aforementioned issue has not been addressed owing to the extreme service condition and high test cost, with current research often limited to simulations of only two-dimensional models, or local impact deformation analysis. Existing studies have revealed that surface texture can weaken the wear damage of materials to a certain extent. The finite element simulation analysis method has become an effective way to analyze the friction and wear behavior of materials, so that the wear of the slider can be reasonably predicted and evaluated. In the present work, a finite element three-dimensional wear model consisting of a 0Cr18Ni9Ti stainless steel slider and a U71Mn steel rail for railway track was established. First of all, in order to accurately and effectively simulate the wear process of a rocket sled slider, the widely recognized and mature Archard theory and finite element discretization were used as the wear calculation principle and numerical calculation method, respectively. Additionally, to avoid forming mesh distortions caused by repositioning the surface mesh nodes during the wear process of the rocket sled slider, a nonlinear adaptive geometric update strategy was adopted to redivide the mesh when mesh distortion occurred. Furthermore, the elastoplastic deformation of the rocket sled slider was also taken into account; a bilinear isotropic hardening constitutive model of the slider material was provided. Meanwhile, one kind grooved surface texture was designed, with the grooves parallel to the sliding direction. In the simulation, the width and depth of the grooved surface texture was 50 equal parts and 100 equal parts of the symmetrical model width (13.5 mm) — namely 270 μm and 135 μm, respectively — while the texture density was varied between values of 22%, 28%, and 34%. The wear simulation of the smooth surface and the groove-textured surface of the rocket sled slider were carried out. Finally, any changes to contact characteristics during the wear process of the slider such as contact surface wear, von Mises stress, and contact pressure were revealed. The results showed that the smooth surface which presented a significant front-end effect, might lead to the occurrence of eccentric wear. On the other hand, the grooved surface texture have resulted in a uniform stress distribution and stable gradient pressure, and would significantly reduce the wear of slider. The increase in texture density was found to promote uniform wear at the friction interface. In addition, positive variations in uniform stress distribution and stable gradient change were also demonstrated as the texture density increased on groove-textured rocket sled slider, which alleviated the stress concentration and has avoided severe wear of the slider during long time service. Meanwhile, the contact pressure also increased with the increase of texture density, which brought the contact surface in closer contact with the target surface, with the gap between the two appearing smaller. This is able to effectively avoid three-body wear that is induced by formed abrasive particles or debris from wear. Therefore, only the factor of texture density is deserved to be considered, with the 34% texture density the most appropriate value. The finite element simulation suggested that the grooved surface texture was able to reduce wear, which can provide technical reference and theoretical support for the realization of a rocket sled slider with anti-friction properties, anti-wear properties, and structural designability. |
| Key words: rocket sled slider finite element simulation wear grooved surface texture |
