Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position

This article evaluates the redistribution of forces to the parachute harness during an opening shock load and also defines the ultimate limit load of the personal parachute harness by specifying the weakest construction element and its load capacity. The primary goal of this research was not only to...

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Main Authors: Robert Grim, Robert Popela, Ivo Jebáček, Marek Horák, Jan Šplíchal
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Aerospace
Subjects:
Online Access:https://www.mdpi.com/2226-4310/10/1/83
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author Robert Grim
Robert Popela
Ivo Jebáček
Marek Horák
Jan Šplíchal
author_facet Robert Grim
Robert Popela
Ivo Jebáček
Marek Horák
Jan Šplíchal
author_sort Robert Grim
collection DOAJ
description This article evaluates the redistribution of forces to the parachute harness during an opening shock load and also defines the ultimate limit load of the personal parachute harness by specifying the weakest construction element and its load capacity. The primary goal of this research was not only to detect the critical elements but also to gain an understanding of the force redistribution at various load levels, which could represent changes in body mass or aerodynamic properties of the parachute during the opening phase. To capture all the phenomena of the parachutist’s body deceleration, this study also includes loading the body out of the steady descending position and asymmetrical cases. Thus, the result represents not only idealized loading but also realistic limit cases, such as asymmetric canopy inflation or system activation when the skydiver is in a non-standard position. The results revealed a significant difference in the strength utilization of the individual components. Specifically, the back webbing was found to carry a fractional load compared to the other webbing used in the design in most of the scenarios tested. Reaching the maximum allowable strength was first achieved in the asymmetric load test case, where the total force would be equal to the value of 7.963 kN, which corresponds to the maximum permissible strength of the carabiner on the measuring element three. In the same test case, the second weakest point would reach the limiting load force when the entire harness is loaded with 67.89 kN. This information and the subsequent analysis of the individual nodes provide a great opportunity for further strength and weight optimization of the design, without reducing the load capacity of the harness as a system. The findings of this study will be used for further testing and possible harness robustness optimization for both military and sport parachuting.
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spelling doaj.art-113aad7fff61452f8b9995c5f8e78be72023-11-30T20:44:08ZengMDPI AGAerospace2226-43102023-01-011018310.3390/aerospace10010083Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body PositionRobert Grim0Robert Popela1Ivo Jebáček2Marek Horák3Jan Šplíchal4Institute of Aerospace Engineering, Brno University of Technology, 60190 Brno, Czech RepublicInstitute of Aerospace Engineering, Brno University of Technology, 60190 Brno, Czech RepublicInstitute of Aerospace Engineering, Brno University of Technology, 60190 Brno, Czech RepublicInstitute of Aerospace Engineering, Brno University of Technology, 60190 Brno, Czech RepublicInstitute of Aerospace Engineering, Brno University of Technology, 60190 Brno, Czech RepublicThis article evaluates the redistribution of forces to the parachute harness during an opening shock load and also defines the ultimate limit load of the personal parachute harness by specifying the weakest construction element and its load capacity. The primary goal of this research was not only to detect the critical elements but also to gain an understanding of the force redistribution at various load levels, which could represent changes in body mass or aerodynamic properties of the parachute during the opening phase. To capture all the phenomena of the parachutist’s body deceleration, this study also includes loading the body out of the steady descending position and asymmetrical cases. Thus, the result represents not only idealized loading but also realistic limit cases, such as asymmetric canopy inflation or system activation when the skydiver is in a non-standard position. The results revealed a significant difference in the strength utilization of the individual components. Specifically, the back webbing was found to carry a fractional load compared to the other webbing used in the design in most of the scenarios tested. Reaching the maximum allowable strength was first achieved in the asymmetric load test case, where the total force would be equal to the value of 7.963 kN, which corresponds to the maximum permissible strength of the carabiner on the measuring element three. In the same test case, the second weakest point would reach the limiting load force when the entire harness is loaded with 67.89 kN. This information and the subsequent analysis of the individual nodes provide a great opportunity for further strength and weight optimization of the design, without reducing the load capacity of the harness as a system. The findings of this study will be used for further testing and possible harness robustness optimization for both military and sport parachuting.https://www.mdpi.com/2226-4310/10/1/83parachute harnessopening loadlimit load
spellingShingle Robert Grim
Robert Popela
Ivo Jebáček
Marek Horák
Jan Šplíchal
Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position
Aerospace
parachute harness
opening load
limit load
title Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position
title_full Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position
title_fullStr Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position
title_full_unstemmed Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position
title_short Determination of the Parachute Harness Critical Load Based on Load Distribution into Individual Straps with Respect of the Skydiver’s Body Position
title_sort determination of the parachute harness critical load based on load distribution into individual straps with respect of the skydiver s body position
topic parachute harness
opening load
limit load
url https://www.mdpi.com/2226-4310/10/1/83
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