CV


FA
Hossein Ashrafi

Hossein Ashrafi

Assistant Professor

hashrafi@kashanu.ac.ir

College: Faculty of Mechanical Engineering

Department: Mechanical Engineering - Solid Design

Degree: Ph.D

CV
FA
Hossein Ashrafi

Assistant Professor Hossein Ashrafi

hashrafi@kashanu.ac.ir
College: Faculty of Mechanical Engineering - Department: Mechanical Engineering - Solid Design Degree: Ph.D |

  •  Position: Assistant Professor of Solid Mechanics and Applied Design
  •  Institution: Faculty of Mechanical Engineering, University of Kashan, Iran
  •  Researcher ID: P-8090-2014
  •  Scopus Author ID: 12793997500
  •  M.Sc. (Sept. 2005 – August 2008): Graduated from Shiraz University, with Overall GPA 17.67 out of 20.
  •  Ph.D. (Sept. 2010 – August 2014): Graduated from K.N. Toosi University, with Overall GPA 19.43 out of 20.
  • Address: No. 316, 3rd Floor, Faculty of Mech. Eng., University of Kashan, Ghotbravandi Blvd., Kashan, Iran
  • ​P.O. Box:  8731751167
  • Telephone:  (+98) 31 55913439
  • Fax:  (+98) 31 55913444
  • URL:  https://faculty.kashanu.ac.ir/hashrafi/en​

 

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Nonlinear Viscoelastic Modeling of ACL Soft Tissue: A Weibull-Based Constitutive Approach

AuthorsZahra sadat Sajadi,Parisa Mirzania
Conference TitleThe 3rd National Conference on Industrial Technologies in Mechanical Engineering
Holding Date of Conference2025-04-30 - 2025-05-02
Event Place1 - اراک
Presented byArak University of Technology
PresentationSPEECH
Conference LevelNational Conferences
KeywordsACL, Viscoelasticity, Weibull distribution, Creep, Stress relaxation, Collagen fibers

Abstract

Anterior cruciate ligament (ACL) plays a vital role in the mechanical stability of the knee joint. The biomechanical behavior of ACL is primarily influenced by its hierarchical collagen structure and viscoelastic properties. This paper presents a nonlinear viscoelastic constitutive model to characterize creep and stress relaxation behaviors of ACL soft tissue. The model assumes collagen fibers as nonlinear elastic elements governed by the Weibull probability distribution, while the ground substance is modeled as a Maxwell-type viscoelastic network. The total stress response is derived by superposing the mechanical contributions of the collagen fibrils and the proteoglycan-rich matrix. Simulation results indicate that the model can replicate major viscoelastic phenomena such as stress relaxation, creep deformation, and hysteresis observed in experimental data. This approach provides an accurate representation of timedependent mechanical responses of biological soft tissues and could aid in the design of biomimetic grafts or rehabilitation protocols following ACL injuries.