东北大学学报:自然科学版 ›› 2015, Vol. 36 ›› Issue (9): 1337-1341.DOI: 10.3969/j.issn.1005-3026.2015.09.026

• 资源与土木工程 • 上一篇    下一篇

弥散裂缝模型水力压裂数值方法的网格敏感性分析

李明1,2, 梁力1, GUO Pei-jun2, 李鑫1   

  1. (1. 东北大学 资源与土木工程学院, 辽宁 沈阳110819; 2. 麦克马斯特大学 土木工程系, 安大略 哈密尔顿L8S4L8)
  • 收稿日期:2014-07-14 修回日期:2014-07-14 出版日期:2015-09-15 发布日期:2015-09-14
  • 通讯作者: 李明
  • 作者简介:李明(1980-),男,辽宁沈阳人,东北大学讲师,麦克马斯特大学博士后研究人员; 梁力(1955-),男,辽宁丹东人,东北大学教授,博士生导师; GUO Pei-jun(1966-),男,河南林州人,麦克马斯特大学终身教授,博士生导师.
  • 基金资助:
    中央高校基本科研业务费专项资金资助项目(N110301001); 国家自然科学基金资助项目(51474048); 高等学校博士学科点专项科研基金资助项目(20120042110001).

Mesh Sensitivity Analysis of the Solution to Hydraulic Fracture Problems Based on a Smeared Crack Model

LI Ming1,2, LIANG Li1, GUO Pei-jun2, LI Xin1   

  1. 1. School of Resources & Civil Engineering, Northeastern University, Shenyang 110819, China; 2. Department of Civil Engineering, McMaster University, Hamilton L8S4L8, Canada.
  • Received:2014-07-14 Revised:2014-07-14 Online:2015-09-15 Published:2015-09-14
  • Contact: LI Ming
  • About author:-
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摘要: 在非线性岩土/石力学问题中,网格质量是影响计算结果的一个重要因素.本文分析了弥散裂缝模型水力压裂数值求解方法中单元高宽比(AR)对计算结果的影响.材料的弹性部分采用线弹性和多孔弹性两种本构关系,屈服和破坏准则采用Drucker-Prager(DP)和Mohr-Coulomb(MC)两种模型.通过综合分析,无论采用何种本构关系,均存在网格敏感性问题.当裂缝的传播方向已知时,可以将单元的AR值控制在2.8~8.0之间,以避免弥散裂缝模型的网格敏感性问题,并得到稳定的结果.如果裂缝传播方向未知,建议使用线弹性本构关系和DP或者MC塑性模型,同时建议AR的取值为1.0.

关键词: 网格敏感性, 水力压裂, 弥散裂缝模型, 单元高宽比(AR), 有限单元法

Abstract: Mesh quality is an important factor that affects the simulation results in nonlinear soil/rock mechanic problems. The effect of aspect ratio of element (AR) on calculation was analyzed in numerical solution of hydraulic fracture for the smeared crack model. Elasticity was measured by adopting the porous elastic (PE) and linear elastic (LE) constitutive models. Regarding to material yielding and failure, both the Drucker-Prager (DP) and Mohr-Coulomb (MC) models were considered. Based on a comprehensive analysis, it is concluded that no matter which constitutive model is adopted, there always exists mesh sensitivity. If the direction of fracture propagation is known, the AR should be between 2.8 and 8.0 to obtain stable results. If the direction is unknown, it is recommended that the LE constitutive model as well as the MC/DP plasticity model should be used together with the AR equal to 1.0.

Key words: mesh sensitivity, hydraulic fracture, smeared crack model, aspect ratio of element (AR), finite element method

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