基于破碎能耗的粗颗粒料本构模型

现有的考虑颗粒破碎的本构模型主要是通过引入颗粒破碎率来反映颗粒破碎对材料力学性质的影响，由于颗粒破碎率只是粗颗粒料在受外荷作用下的一种外部表现，在测定的其它参数中实际上已经包含了颗粒破碎的影响，因此为反映颗粒破碎而引入颗粒破碎率的方法是不合适的。基于Ueng和Chen剪胀方程，通过分析三轴剪切试验过程中的能量平衡，提出了考虑颗粒破碎的剪胀方程及其参数确定方法。将Rowe剪胀方程和考虑颗粒破碎的剪胀方程分别引入Duncan E-非线性模型和沈珠江“南水”双曲服面模型，通过与三轴CD剪切试验成果的对比分析和工程实例的有限元数值分析，表明所提模型可较好地反映材料的剪胀特性。如采用弹塑性模型尚能反映颗粒破碎在增加变形的同时降低了材料的强度等特性，验证了所提模型的合理性和可靠性。与现有的考虑颗粒破碎的本构模型相比，所提模型具有试验工作量小、参数少和参数物理意义明确等优点，便于在工程中推广使用。

Constitutive model for coarse granular materials based on breakage energy

The existing constitutive models incorporating particle breakage mainly introduce the particle breakage index to reflect the influences of the particle breakage on the mechanical properties of coarse granular materials. Because of the external display of the particle breakage index of coarse particles under external load, the measured parameters actually include the influences of the particle breakage, and the methods for the particle breakage into which by introducing the particle breakage index are not suitable. Based on the Ueng’s and Chen’s dilatancy formulae, the dilatancy equation considering the particle breakage and the relevant methods for its parameters are proposed by analyzing the energy equilibrium problems in the process of triaxial CD tests. The Rowe’s dilatancy formula and the proposed dilatancy equation considering the particle breakage are respectively introduced into the Duncan-Chang E- model and the NHRI double-yield face model by Shen Zhujiang. Through the comparison with the results of triaxial CD tests and the finite element numerical analysis of a case study, it is shown that the proposed model can satisfactorily reflect the dilatancy properties of the materials, for example, the elastoplastic model may depict the increase of the deformation and simultaneously the decrease of the strength of the materials during the particle breakage. The rationality and reliability of the proposed model are thus validated. Compared with the existing constitutive models considering the particle breakage, the proposed model has the advantages of small test workload, few parameters and clear significance of parameters, etc., and it is convenient to be popularized in projects.