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Gavelin, Anders
Publications (7 of 7) Show all publications
Gavelin, A., Iraeus, J., Lindquist, M. & Oldenburg, M. (2010). Evaluation of finite element models of seat structures with integrated safety belts using full-scale experiments (ed.). Paper presented at . International Journal of Crashworthiness, 15(3), 265-280
Open this publication in new window or tab >>Evaluation of finite element models of seat structures with integrated safety belts using full-scale experiments
2010 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 15, no 3, p. 265-280Article in journal (Refereed) Published
Abstract [en]

Any numerical model needs to be evaluated in order to perform as accurately as possible. The aim of the present study is to develop an FE model of a seat structure with integrated safety belts evaluated to full-scale experiments. Simplified seat structures with 3-point integrated safety belt configurations and corresponding FE models were established. The dimension and the material states of the seat back frame were varied. A 50th percentile Hybrid III dummy was used as occupant. A number of biomechanical and mechanical responses of both experiments and simulations were compared and evaluated. The majority of the simulated responses showed good agreement with or slightly underestimated the corresponding experimental responses during belt loading but differed during belt unloading in some cases. Some inadequacies of the FE model were discovered and areas for further development are suggested. The FE model developed and evaluated in the present study may well be used in future studies

National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-2869 (URN)10.1080/13588260903250994 (DOI)000280281200004 ()2-s2.0-77954928412 (Scopus ID)0970ec80-a12d-11df-a707-000ea68e967b (Local ID)0970ec80-a12d-11df-a707-000ea68e967b (Archive number)0970ec80-a12d-11df-a707-000ea68e967b (OAI)
Note
Validerad; 2010; 20100806 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Gavelin, A., Lindquist, M., Häggblad, H.-Å. & Oldenburg, M. (2010). Methodology for mass minimisation of a seat structure with integrated safety belts constrained by biomechanical responses on the occupant in frontal crashes (ed.). Paper presented at . International Journal of Crashworthiness, 15(4), 343-355
Open this publication in new window or tab >>Methodology for mass minimisation of a seat structure with integrated safety belts constrained by biomechanical responses on the occupant in frontal crashes
2010 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 15, no 4, p. 343-355Article in journal (Refereed) Published
Abstract [en]

A methodology using finite element (FE) modelling and simulation with a property-based model (PBM) is presented. A generic 3-D FE model of a seat structure with a three-point seat-integrated safety belt configuration was established. A 50th percentile Hybrid III FE dummy model was used as occupant. Metamodelling techniques were used in optimisation calculations performed in two steps. Step 1: Six separate optimisations minimising biomechanical responses of the FE dummy model. Step 2: Four separate optimisations with different start values of the design variables, with the total mass of the seat structure as objective function and with the minimised biomechanical responses from Step 1 as constraint values. Six design variables were used in both Step 1 and Step 2. The four optimisations performed in Step 2 generated four different results of the total mass. Thus, different local minima were found instead of one single global minimum. The presented methodology with a PBM may be used in a concept design phase. Some issues concerning the FE model suggest further improvement.

Keywords
Technology - Engineering mechanics, Teknikvetenskap - Teknisk mekanik
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-2659 (URN)10.1080/13588260903385550 (DOI)000282581700001 ()2-s2.0-77957837940 (Scopus ID)04fd34c0-db6f-11df-8b36-000ea68e967b (Local ID)04fd34c0-db6f-11df-8b36-000ea68e967b (Archive number)04fd34c0-db6f-11df-8b36-000ea68e967b (OAI)
Note
Validerad; 2010; 20101019 (mo)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Gavelin, A. (2008). Studies on structural and biomechanical responses in seat integrated safety belt configurations (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Studies on structural and biomechanical responses in seat integrated safety belt configurations
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The common 3-point safety belt usually has some anchor points on the car body. However, it is also possible to mount all anchor points on the seat structure. In general, different studies show some advantages with seat integrated safety belts. Thus, further investigations are motivated. One safety advantage appears in the case of so-called small overlap crashes. Also, the ride-down distance of the occupant may be increased by allowing controlled energy absorbing deformation of the seat structure. Further, methods that can be used to minimize the weight of seat structures with integrated safety belts are of interest. A complement to full scale crash tests is the use of numerical models and numerical simulation, typically finite element (FE) analysis. Research and development of numerical models are constantly improved. In general, any type of numerical model needs to be evaluated to physical tests in order to make it behave as realistic as possible. The purpose of the present thesis was to study seat structures with integrated safety belts with a design that may intentionally deform and absorb energy during a crash. The approach was to use numerical models and numerical simulation and to investigate both biomechanical and mechanical responses. The aim is to create a basis for future research in the design of seat structures with integrated safety belts. In Paper A and B, parametric studies comparing integrated 3- and 4-point safety belt configurations relative to common 3-point configurations are presented. A number of mechanical parameters were varied. Biomechanical responses of the Hybrid III (HIII) FE-dummy model used as occupant were studied. In Paper C, the creation and evaluation of a human FE-model of a 50th percentile male is presented. The evaluation was made to results from studies with post mortem human subjects (PMHS). In Paper D, a conceptual methodology for mass minimization of a property based model (PBM) of a seat structure with an integrated 3-point safety belt configuration and with a HIII FE-dummy model used as occupant is presented. Both mechanical and biomechanical constraints were used as well as different start values of the design variables. In Paper E, the evaluation of FE-models of simplified seat structures with integrated 3-point safety belt configurations to a number of full scale experiments in the form of sled tests with a HIII crash test dummy used as occupant is presented. The studies in Paper A and B reveals that with an adequate combination of mechanical properties of the seat structure it should be possible to achieve equal or lower biomechanical responses of the occupant with a seat integrated safety belt configuration compared to a common. The seat integrated 4-point configurations in these studies performed poorer than the corresponding 3-point in general. An important issue is that belt- webbing distribution between lap and torso belt parts is allowed. The study in Paper C showed that the created and evaluated human FE-model could be used to further explore injury producing mechanisms. However, in order to achieve a fully evaluated human FE-model there is a need for both further development and more reference tests with PMHS. In Paper D, the study showed that the presented methodology may be used in a concept phase of a design process. The optimization runs with different start values of the design variables found a number of different local minima instead of one global minimum. The dynamics of the system was highly non-linear. To find an optimal combination of mechanical properties and biomechanical responses, a compromise appears to be needed. The evaluated FE-model in Paper E may be used in simulations that consider both biomechanical and mechanical responses. The majority of the simulated responses showed good agreement with or slightly underestimated the experimental responses. Some issues of the FE-model suggest areas for further development. The FE-model could be used as a base for further studies.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2008. p. 42
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544 ; 2008:12
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-26683 (URN)f85d4640-0229-11dd-9241-000ea68e967b (Local ID)f85d4640-0229-11dd-9241-000ea68e967b (Archive number)f85d4640-0229-11dd-9241-000ea68e967b (OAI)
Note

Godkänd; 2008; 20080404 (ysko)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-02-27Bibliographically approved
Gavelin, A., Lindquist, M. & Oldenburg, M. (2007). Modelling and simulation of seat-integrated safety belts including studies of pelvis and torso responses in frontal crashes (ed.). Paper presented at . International Journal of Crashworthiness, 12(4), 367-379
Open this publication in new window or tab >>Modelling and simulation of seat-integrated safety belts including studies of pelvis and torso responses in frontal crashes
2007 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 12, no 4, p. 367-379Article in journal (Refereed) Published
Abstract [en]

The aim of the present study is to investigate how the physical properties influence the interaction of the seat back frame and the safety belt. Seat-integrated 3- and 4-point configurations with both non-rigid and rigid seat back frames were compared with common 3-point configurations with anchor points on the car body. The LS-DYNA FE-analysis software was used in order to perform frontal crash simulations with a belted 50th percentile Hybrid III FE-dummy model as occupant. The belt-webbing distribution between the lap and the torso belts via a slip-ring and in combination with a non-rigid seat back frame increases the ride-down efficiency compared to a system with no belt-webbing distribution. No tendencies of pelvis submarining were observed regardless of belt configuration. The dynamic response of the seat back frame has some influence on the ride-down efficiency.

National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-16335 (URN)10.1080/13588260701482906 (DOI)000250440300004 ()2-s2.0-41549126026 (Scopus ID)ff6978c0-8202-11dc-896e-000ea68e967b (Local ID)ff6978c0-8202-11dc-896e-000ea68e967b (Archive number)ff6978c0-8202-11dc-896e-000ea68e967b (OAI)
Note
Validerad; 2007; 20071024 (andgav)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Gavelin, A., Lindquist, M. & Oldenburg, M. (2007). Numerical studies concerning upper neck and head responses in frontal crashes with seat-integrated safety belts (ed.). Paper presented at . International Journal of Crashworthiness, 12(5), 465-479
Open this publication in new window or tab >>Numerical studies concerning upper neck and head responses in frontal crashes with seat-integrated safety belts
2007 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 12, no 5, p. 465-479Article in journal (Refereed) Published
Abstract [en]

Mitigation of neck and head injuries is critical in automotive occupant protection. The aim of the present study is to investigate how the physical properties influence the interaction of the seat back frame and the safety belt. Seat integrated 3- and 4-point configurations with both non-rigid and rigid seat back frames were compared with 3-point configurations with anchor points on the car body. The LS-DYNA FE-analysis software was used in order to perform frontal crash simulations with a belted 50th percentile Hybrid III dummy model as occupant. The belt-webbing distribution between the lap and the torso belts via a slip-ring and in combination with a non-rigid seat back frame had an advantageous influence concerning the loads of the upper neck and injury criteria compared to a system with no belt-webbing distribution.

National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-16043 (URN)10.1080/13588260701483243 (DOI)000251164600002 ()2-s2.0-41549128559 (Scopus ID)fa057020-8205-11dc-896e-000ea68e967b (Local ID)fa057020-8205-11dc-896e-000ea68e967b (Archive number)fa057020-8205-11dc-896e-000ea68e967b (OAI)
Note
Validerad; 2007; 20071024 (andgav)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Gavelin, A. (2007). Seat Integrated Safety Belts: A Parametric Study Using Finite Element Simulations (ed.). In: (Ed.), Niklas Davidsson; Elianne Wassvik (Ed.), Svenska Mekanikdagar 2007: Program och abstracts. Paper presented at Svenska Mekanikdagar 2007 : 13/06/2007 - 15/06/2007 (pp. 115). Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Seat Integrated Safety Belts: A Parametric Study Using Finite Element Simulations
2007 (English)In: Svenska Mekanikdagar 2007: Program och abstracts / [ed] Niklas Davidsson; Elianne Wassvik, Luleå: Luleå tekniska universitet, 2007, p. 115-Conference paper (Other academic)
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2007
Series
Research report / Luleå University of Technology, ISSN 1402-1528 ; 2007:10
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-30655 (URN)48744cc0-5c51-11dc-a955-000ea68e967b (Local ID)48744cc0-5c51-11dc-a955-000ea68e967b (Archive number)48744cc0-5c51-11dc-a955-000ea68e967b (OAI)
Conference
Svenska Mekanikdagar 2007 : 13/06/2007 - 15/06/2007
Note

Godkänd; 2007; 20070906 (ysko)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-02-27Bibliographically approved
Gavelin, A. (2006). Seat integrated safety belts: a parametric study using finite element simulations (ed.). (Licentiate dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Seat integrated safety belts: a parametric study using finite element simulations
2006 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In recent years an increasing interest has evolved concerning seat integrated safety belts in cars, regarding both 3- and 4-point belts in various configurations. One safety advantage of seat integrated safety belts appears in the case of so-called small overlap crashes. One consequence of a small overlap crash can be that the colliding cars strike each other's sides hitting both the A- and B-pillar. Hence, the A- as well as the B-pillar are pushed inwards and backwards. In this case, belt anchor points on the B-pillar may also be pushed backwards and the belt will be stretched over the occupant. The purpose of the present study was to investigate seat integrated safety belt configurations that may involve a seat structure design that intentionally deforms and absorbs energy during a crash. Common 3-point configurations were used as references. The aim was to investigate how the physical properties influence the interaction of the seat back frame and the safety belt. Numerical simulations were carried out using the explicit LS-DYNA FE-analysis software. A FE-model of a seat structure, floor pan and B-pillar was established. A 50th percentile Hybrid III FE-dummy model was used as occupant and for studying the biomechanical responses. Different physical properties of the seat structure and different belt load limit forces were used as parametric variables. Only frontal crashes were considered. Responses concerning chest deflection, head- and chest displacement, change of pelvis angle, pelvis submarining tendency, lap- and torso belt forces, seat back frame deflection, ride-down efficiency, seat structure natural frequency, upper neck loads and neck injury criteria were studied. The results indicate that the belt-webbing distribution between the lap and the torso belts via a slip-ring and in combination with a non-rigid seat back frame increases the ride-down efficiency compared to a system with no belt-webbing distribution. Further, the combined use of different energy absorption mechanisms influences the biomechanical response as well as the structural response of an integrated safety belt configuration. An optimal solution with respect to multiple objectives requires a proper combination of parameters. Beside the optimisation of traditional biomechanical responses, the multiple objectives can be the minimisation of weight and cost as well as optimal control of passenger kinematics. The present study will hopefully create a basis for future research and possibly for the design of seat integrated safety belts.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2006. p. 21
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757 ; 2006:21
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-26588 (URN)f081e790-9fd4-11db-8975-000ea68e967b (Local ID)f081e790-9fd4-11db-8975-000ea68e967b (Archive number)f081e790-9fd4-11db-8975-000ea68e967b (OAI)
Note

Godkänd; 2006; 20070109 (haneit)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-02-27Bibliographically approved

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