A continuum mechanical approach to model asphalt
A continuum mechanical approach to model asphalt
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DOI：
10.1080/10298436.2014.927065
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发表时间：
2015-02
影响因子：
3.8
通讯作者：
Christoph Zopf;Mario A. García;M. Kaliske
中科院分区：
文献类型：
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作者：
Christoph Zopf;Mario A. García;M. Kaliske
本文的目的是从结构力学的角度对轮胎-路面-路面相互作用分析做出贡献。将所提出的沥青材料模型用于分析载重汽车轮胎循环荷载作用下沥青路面的应变-应力相关性。对于轮胎与路面的相互作用以及轮胎与路面的相互作用，采用有限元方法进行分析。材料模型的建立是基于圆柱体试件的三轴材料试验。沥青材料具有弹性、粘性(速率相关)和塑性特性。为了使该模型也能用于路面内的大变形，它是针对有限应变而开发的。该方法由五个并行的流变本构分支组成。采用非线性弹性材料模型来描述材料的弹性行为。塑性效应由内时摩擦单元来考虑。一个Maxwell单元和两个分数Maxwell单元代表了模型的粘弹性行为。分数元素的考虑通常用于表征循环加载的材料，如沥青。此外，它还可以用很少的材料参数来表示粘弹性特性。对于分数元素，材料参数决定了流变元素的特征在弹簧()和仪表盘()之间的过渡。最后，将所提出的模型用于路面在瞬时循环轮胎荷载作用下的仿真。从而得到了每次荷载循环后路面变形的增加值。考虑到这一结果，对沥青路面的长期行为进行了外推，并根据荷载循环次数计算了车辙发展。
The goal of this paper is to contribute to tire–pavement-interaction analyses from a structural mechanics point of view. The proposed asphalt material model is used to analyse the strain–stress dependencies of an asphalt pavement which is cyclically loaded by a truck tire. For the analysis of tire and pavement as well as its interaction, a finite element approach is utilised. The development of the material model is based on triaxial material tests of cylindrical specimens. The asphalt material is characterised by elastic, viscous (rate-dependent) and plastic behaviour. In order to enable the use of the model also for large deformations within the pavement, it is developed for finite strains. The proposed approach consists of five rheological constitutive branches in parallel. A nonlinear elastic material model is used, which represents the elastic behaviour. The plastic effects are considered by an endochronic frictional element. One Maxwell element and two fractional Maxwell elements represent the viscoelastic behaviour of the model. The consideration of fractional elements is commonly used for the characterisation of cyclicly loaded materials like asphalt. Furthermore, it enables the representation of viscoelastic properties with few material parameters. For the fractional element, a material parameter determines the transition of the rheological element's features between spring () and dashpot (). The proposed model is finally considered within a simulation of a pavement at transient cyclic tire loading. Hence, the increase of the pavement deformation after each load cycle is obtained. Taking this result into account, the long-term behaviour of asphalt pavement is extrapolated and the development of rutting is computed in dependency on the number of load cycles.