Numerical and experimental development of an “Accelerated Repeated Rolling Wheel Load Simulator” (ARROWS)

“加速重复滚轮负载模拟器”（ARROWS）的数值和实验开发

• 批准号: 414936990
• 负责人: Professor Dr.-Ing. Michael Kaliske
• 金额: --
• 依托单位: Lehrstuhl und Institut für Straßenwesen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/414936990?language=en
• 关键词: Numerical; experimental; development; Accelerated; Repeated

In the mechanistic design of flexible pavements under consideration of moving loads, particular attention is paid to achieving a realistic description of fatigue phenomena in asphalt layers due to tensile stresses. If the resulting external loading exceeds the fatigue resistance of the asphalt, fatigue cracking occurs. The initiation of micro and macro cracks is highly temperature dependant as well as stress dependant. However, current experimental setups exhibit stress states and mechanisms of crack propagation that differ strongly from those present in real pavements. Numerical approaches are limited to a reproduction and depiction of single components of the underlying phenomena or generally require further development to allow for applicable results. Therefore, the proposed research project a numerical-experimental approach and a realistic reproduction of loading conditions of asphalt layers under moving loads are pursued. The numerical and experimental development of an “Accelerated Repeated Rolling Wheel Load Simulator” (ARROWS) represents the core of the research project and aims to allow for accurate knowledge on the service life as well as the fatigue susceptibility of pavement structures with asphalt layers. The focus is on realising a realistic depiction of crack formation and crack propagation under real loading scenarios including magnitude, loading velocity and loading progressions.In the initial phase of the joint research project a numerical validation (simulation of the loading conditions from stationary tyre passes and due to the developed ARROWS testing device) shall be provided and the respective loading conditions are to be compared with one another. Simultaneously, the numerical conception of the testing device is carried out (design details, operative stability). Furthermore, the experimental conception of the device will be further developed. The focus of the research project is the experimental characterisation and the numerical representation of damage and healing phenomena of asphalt mixtures in pavements under moving loads. Based on this, a numerical model shall be developed to allow for long term predictions with a large number of loading cycles and long test durations. Experiments are conducted to identify the model parameters for a precise description of short-term and long-term behaviour of asphalt (material and structure). Initial structural tests allow for an evaluation of the prediction quality of the selected simulation approach for long-term behaviour; this is based on real-time accelerated testing by means of the construction of a scaled ARROWS device. Finally, the attained insight will be inspected with regard to transferability of assumptions to an unscaled, full-sized ARROWS device.

在考虑移动荷载作用下的柔性路面力学设计中，特别注重对拉应力引起的沥青层疲劳现象进行逼真的描述。如果产生的外部荷载超过沥青的疲劳抗力，就会发生疲劳开裂。微裂纹和宏观裂纹的萌生高度依赖于温度和应力。然而，目前的实验装置显示出的应力状态和裂缝扩展机制与真实路面上的完全不同。数值方法仅限于再现和描述潜在现象的单个组成部分，或者通常需要进一步发展才能产生适用的结果。因此，提出的研究项目是一种数值试验方法，并追求移动荷载下沥青层荷载条件的真实再现。“加速重复滚动车轮载荷模拟器”(ARROWS)的数值和实验开发是该研究项目的核心，旨在准确了解沥青路面结构的使用寿命和疲劳敏感性。重点是实现真实的裂纹形成和裂纹扩展的描述，在真实的加载场景下，包括大小、加载速度和加载进度。在联合研究项目的初始阶段，将提供数值验证(模拟静止轮胎通过和由于开发的箭头测试装置而产生的加载条件)，并对各自的加载条件进行相互比较。同时，对试验装置进行了数值构思(设计细节、运行稳定性)。此外，该装置的实验构思还将进一步发展。本课题的研究重点是移动荷载作用下沥青混合料在路面中损伤和愈合现象的实验表征和数值表示。在此基础上，应开发一个数值模型，以便在大量加载循环和长试验持续时间的情况下进行长期预测。为准确描述沥青(材料和结构)的短期和长期行为，进行了实验识别模型参数。最初的结构测试可以评估选定的模拟方法对长期行为的预测质量；这是基于通过建造定标箭头装置进行的实时加速测试。最后，将检查所获得的洞察力，关于假设是否可以转移到无比例、全尺寸的箭头设备。