The Penn State Safety Floor: Part II—Reduction of Fall-Related Peak Impact Forces on the FemurSource: Journal of Biomechanical Engineering:;1998:;volume( 120 ):;issue: 004::page 527DOI: 10.1115/1.2798023Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: The goal of this study was to develop and validate a finite element model (FEM) for use in the design of a flooring system that would provide a stable walking surface during normal locomotion but would also deform elastically under higher loads, such as those resulting from falls. The new flooring system is designed to reduce the peak force on the femoral neck during a lateral fall onto the hip. The new flooring system is passive in nature and exhibits two distinct stiffnesses. During normal activities, the floor remains essentially rigid. Upon impact, the floor collapses and becomes significantly softer. The flooring system consists of a multitude of columns supporting a continuous walking surface. The columns were designed to remain stiff up to a specific load and, after exceeding this load, to deform elastically. The flooring returns to its original shape after impact. Part I of this study presented finite element and experimental results demonstrating that the floor deflection during normal walking remained less than 2 mm. To facilitate the floor’s development further, a nonlinear finite element model simulating the transient-impact response of a human hip against various floor configurations was developed. Nonlinearities included in the finite element models were: changing topology of deformable-body-to-deformable-body contact, snap-through buckling, soft tissue stiffness and damping, and large deformations. Experimental models developed for validating the finite element model included an anthropomorphic hip, an impact delivery mechanism, a data collection system, and four hand-fabricated floor tiles. The finite element model discussed in this study is shown to capture experimentally observed trends in peak femoral neck force reduction as a function of flooring design parameters. This study also indicates that a floor can be designed that deflects minimally during walking and reduces the peak force on the femoral neck during a fall-related impact by 15.2 percent.
keyword(s): Safety , Force , Stress , Design , Finite element analysis , Buckling , Collapse , Deflection , Shapes , Stiffness , Tiles , Topology , Soft tissues , Data collection , Mechanisms , Finite element methods , Damping AND Deformation ,
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contributor author | J. A. Casalena | |
contributor author | P. R. Cavanagh | |
contributor author | D. A. Streit | |
contributor author | A. Badre-Alam | |
contributor author | T. C. Ovaert | |
date accessioned | 2017-05-08T23:55:56Z | |
date available | 2017-05-08T23:55:56Z | |
date copyright | August, 1998 | |
date issued | 1998 | |
identifier issn | 0148-0731 | |
identifier other | JBENDY-25999#527_1.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl/handle/yetl/120065 | |
description abstract | The goal of this study was to develop and validate a finite element model (FEM) for use in the design of a flooring system that would provide a stable walking surface during normal locomotion but would also deform elastically under higher loads, such as those resulting from falls. The new flooring system is designed to reduce the peak force on the femoral neck during a lateral fall onto the hip. The new flooring system is passive in nature and exhibits two distinct stiffnesses. During normal activities, the floor remains essentially rigid. Upon impact, the floor collapses and becomes significantly softer. The flooring system consists of a multitude of columns supporting a continuous walking surface. The columns were designed to remain stiff up to a specific load and, after exceeding this load, to deform elastically. The flooring returns to its original shape after impact. Part I of this study presented finite element and experimental results demonstrating that the floor deflection during normal walking remained less than 2 mm. To facilitate the floor’s development further, a nonlinear finite element model simulating the transient-impact response of a human hip against various floor configurations was developed. Nonlinearities included in the finite element models were: changing topology of deformable-body-to-deformable-body contact, snap-through buckling, soft tissue stiffness and damping, and large deformations. Experimental models developed for validating the finite element model included an anthropomorphic hip, an impact delivery mechanism, a data collection system, and four hand-fabricated floor tiles. The finite element model discussed in this study is shown to capture experimentally observed trends in peak femoral neck force reduction as a function of flooring design parameters. This study also indicates that a floor can be designed that deflects minimally during walking and reduces the peak force on the femoral neck during a fall-related impact by 15.2 percent. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | The Penn State Safety Floor: Part II—Reduction of Fall-Related Peak Impact Forces on the Femur | |
type | Journal Paper | |
journal volume | 120 | |
journal issue | 4 | |
journal title | Journal of Biomechanical Engineering | |
identifier doi | 10.1115/1.2798023 | |
journal fristpage | 527 | |
journal lastpage | 532 | |
identifier eissn | 1528-8951 | |
keywords | Safety | |
keywords | Force | |
keywords | Stress | |
keywords | Design | |
keywords | Finite element analysis | |
keywords | Buckling | |
keywords | Collapse | |
keywords | Deflection | |
keywords | Shapes | |
keywords | Stiffness | |
keywords | Tiles | |
keywords | Topology | |
keywords | Soft tissues | |
keywords | Data collection | |
keywords | Mechanisms | |
keywords | Finite element methods | |
keywords | Damping AND Deformation | |
tree | Journal of Biomechanical Engineering:;1998:;volume( 120 ):;issue: 004 | |
contenttype | Fulltext |