Faculty Advisor or Committee Member

Malcolm H. Ray, Advisor

Faculty Advisor or Committee Member

Leonard D. Albano, Committee Member

Faculty Advisor or Committee Member

Chiara Silvestri, Committee Member

Identifier

etd-083110-133039

Abstract

"Mammalian skeletal muscle is a very complicated biological structure to model due to its non-homogeneous and non-linear material properties as well as its complex geometry. Finite element discrete one-dimensional Hill-based elements are largely used to simulate muscles in both passive and active states. There are, however, several shortfalls to utilizing one-dimensional elements, such as the impossibility to represent muscle physical mass and complex lines of action. Additionally, the use of one-dimensional elements restricts muscle insertion sites to a limited number of nodes causing unrealistic loading distributions in the bones. The behavior of various finite element muscle models was investigated and compared to manually calculated muscle behavior. An improved finite element muscle model consisting of shell elements and Hill-based contractile truss elements in series and parallel was ultimately developed. The muscles of the thigh were then modeled and integrated into an existing 50th percentile musculo-skeletal model of the knee-thigh-hip complex. Impact simulations representing full frontal car crashes were then conducted on the model and the pre-loading effects from active thigh muscles on the femur were investigated and compared to cadaver sled test data. It was found that the active muscles produced a pre-load femoral axial force that acted to slightly stabilize the rate of stress intensification on critical stress areas on the femur. Additionally, the active muscles served to direct the distribution of stress to more concentrated areas on the femoral neck. Furthermore, the pre-load femoral axial force suggests that a higher percentage of injuries to the knee-thigh-hip complex may be due to the effects of active muscles on the femur. "

Publisher

Worcester Polytechnic Institute

Degree Name

MS

Department

Civil & Environmental Engineering

Project Type

Thesis

Date Accepted

2010-08-31

Accessibility

Unrestricted

Subjects

finite element, ls-dyna, frontal crashes, knee-thigh-hip, nhtsa, national highway traffic safety administration, impact engineering, biomechanics, solid mechanics, dynamics, transportation engineering, kth, muscle, hill, beam, truss, spring, contraction

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