{"title":"Stress-strain responses of EPS geofoam upon cyclic simple shearing: Experimental investigations and constitutive modeling","authors":"","doi":"10.1016/j.geotexmem.2024.10.004","DOIUrl":null,"url":null,"abstract":"<div><div>This paper investigates the cyclic simple shearing behaviors of Expanded Polystyrene (EPS) geofoams considering influences of the shear strain amplitude (<em>γ</em><sub>a</sub>), number of shear cycles, shear rate, vertical stress (<em>σ</em><sub>n</sub>), and EPS density (<em>ρ</em><sub>EPS</sub>). The experimental results demonstrate that the cyclic shear stress (<em>τ</em>)-shear strain (<em>γ</em>) relationships of EPS are not sensitive to the shear rate. As the <em>γ</em> exceeds 2%, the EPS yields and its <em>τ</em>-<em>γ</em> relationships and backbone curve become nonlinear. There are linear relationships between the elastic modulus <em>E</em>, elastic shear modulus <em>G</em><sub>e</sub>, and plastic shear modulus <em>G</em><sub>p</sub>. They increase linearly with an increase in the <em>ρ</em><sub>EPS</sub>. The <em>G</em><sub>e</sub> and <em>G</em><sub>p</sub> are not sensitive to the <em>γ</em><sub>a</sub>. The cyclic shear stiffness <em>G</em> increases while the equivalent damping ratio <em>D</em> of EPS decreases with an increase in the <em>σ</em><sub>n</sub> and <em>ρ</em><sub>EPS</sub>. The <em>G</em> decreases while the <em>D</em> increases nonlinearly as the <em>γ</em><sub>a</sub> increases. Empirical models were developed to describe the variations of the <em>G</em><sub>e</sub>, <em>G</em><sub>p</sub>, <em>G</em>, and <em>D</em> with <em>σ</em><sub>n</sub>, <em>ρ</em><sub>EPS</sub>, and <em>γ</em><sub>a</sub>. A modified Hardin-Drnevich model was proposed to describe the backbone curves and <em>τ</em>-<em>γ</em> loops upon cyclic simple shearing, which has achieved good agreement with the experimental measurements and the testing results from the literature.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":null,"pages":null},"PeriodicalIF":4.7000,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geotextiles and Geomembranes","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0266114424001249","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
This paper investigates the cyclic simple shearing behaviors of Expanded Polystyrene (EPS) geofoams considering influences of the shear strain amplitude (γa), number of shear cycles, shear rate, vertical stress (σn), and EPS density (ρEPS). The experimental results demonstrate that the cyclic shear stress (τ)-shear strain (γ) relationships of EPS are not sensitive to the shear rate. As the γ exceeds 2%, the EPS yields and its τ-γ relationships and backbone curve become nonlinear. There are linear relationships between the elastic modulus E, elastic shear modulus Ge, and plastic shear modulus Gp. They increase linearly with an increase in the ρEPS. The Ge and Gp are not sensitive to the γa. The cyclic shear stiffness G increases while the equivalent damping ratio D of EPS decreases with an increase in the σn and ρEPS. The G decreases while the D increases nonlinearly as the γa increases. Empirical models were developed to describe the variations of the Ge, Gp, G, and D with σn, ρEPS, and γa. A modified Hardin-Drnevich model was proposed to describe the backbone curves and τ-γ loops upon cyclic simple shearing, which has achieved good agreement with the experimental measurements and the testing results from the literature.
期刊介绍:
The range of products and their applications has expanded rapidly over the last decade with geotextiles and geomembranes being specified world wide. This rapid growth is paralleled by a virtual explosion of technology. Current reference books and even manufacturers' sponsored publications tend to date very quickly and the need for a vehicle to bring together and discuss the growing body of technology now available has become evident.
Geotextiles and Geomembranes fills this need and provides a forum for the dissemination of information amongst research workers, designers, users and manufacturers. By providing a growing fund of information the journal increases general awareness, prompts further research and assists in the establishment of international codes and regulations.