A Practical Axial Crush Simulation of Glass-Fiber MAT/PA6 Composite Tubes for Application of an Energy Absorber in Automobiles

2021 ◽  
Author(s):  
Geunsu Joo ◽  
Jinbong Kim ◽  
Mungyu Jeong ◽  
Youngchul Kim ◽  
Holger Böhm ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Composite Tubes ◽  
Energy Absorber ◽  
Axial Crush ◽  
Crush Simulation

Experimental investigation into static and dynamic axial crush of composite tubes of glass-fiber mat/PA6 laminates

2020 ◽  
Vol 181 ◽  
pp. 107590 ◽  
Author(s):  
Jinbong Kim ◽  
Mungyu Jeong ◽  
Holger Böhm ◽  
Jonas Richter ◽  
Niels Modler
Keyword(s):  
Experimental Investigation ◽  
Glass Fiber ◽  
Composite Tubes ◽  
Axial Crush

Energy Absorption of Braided Glass Fiber Reinforced Composite Tubes

2000 ◽  
Author(s):  
Shu Ching Quek ◽  
Anthony M. Waas
Keyword(s):  
Glass Fiber ◽  
Energy Absorption ◽  
Damage Mechanics ◽  
Progressive Failure ◽  
Fiber Composite ◽  
Continuum Damage Mechanics ◽  
Composite Tubes ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Composite

Abstract Results from an experimental and analytical study on the behavior of braided glass fiber composite tubes under quasi-static crush conditions are presented. The composite tubes have an initiator plug introduced at one open end (chamfered) while the other end is clamped. This procedure causes the tube to ‘flare’ outwards into fronds and results in the progressive failure of the tube in the axial and hoop direction without global tube buckling. Axial force and axial displacements are measured during these tests in order to assess energy absorption. In addition, readings from strain gages that are placed at critical locations on the tube walls are used to assess the state of strain on the tube walls away from the crush end. During a crush test, the axial load ascended to a maximum value and subsequently settled to a plateau value about which the load oscillated during the progressive crushing of the tube. The oscillations exhibited distinct periodicity. Results from an analytical model that best simulates the failure of these tubes are presented. The model is based on an axisymmetric formulation of the cylindrical shell equations in conjunction with ideas from classical fracture mechanics and continuum damage mechanics.

Dynamic Axial Crush of Automotive Rail-Sized Composite Tubes: Part 2 — Tubes With Braided Reinforcements (Carbon, Kevlar®, and Glass) and Non-Plug Crush Initiators

2002 ◽  
Author(s):  
Alan L. Browne ◽  
Kristin L. Zimmerman
Keyword(s):  
Carbon Fiber ◽  
Fiber Type ◽  
Low Cost ◽  
High Volume ◽  
Woven Fabric ◽  
Composite Tubes ◽  
Fundamental Study ◽  
Axial Crush ◽  
Almost All ◽  
Tube Geometry

This paper documents the braided reinforcement portion of a successful fundamental study of the dynamic axial crush of automotive rail-sized composite tubes. Braided reinforcements were comprised principally of carbon fiber but also of Kevlar® and E-glass and combinations of the three. Fourteen different braids were used, six of which were tri-axial and the remainder bi-axial. Tubes were manufactured using Resin Transfer Molding (RTM) with processing and molding techniques that are suitable for the low cost high volume needs of the automotive industry. Braids were obtained as continuous rolls of tubular sock-like material and pulled over metal mandrels one ply at a time. Carbon fiber tow sizes ranged from 6k to 48k. Dow Derakane 470 vinylester resin was used for all tubes. Tube geometry, a 88.9×88.9 mm square cross section with 2.54 mm thick walls, approximated that of the first 500 mm of the lower rail of a typical mid-size vehicle. Note in particular that tube wall thickness was fixed at a single value in this study. A 45° bevel on the outside edge of the lead end of each tube served as the crush initiator. In total 71 dynamic axial crush tests were conducted. In terms of important findings, consistent with the woven fabric portion of this program [1], desirable dynamic axial crush response was demonstrated for RTM’d automotive rail-sized carbon fiber reinforced tubes. For almost all parameter configurations, the tubes exhibited stable and progressive crush with a reasonably flat plateau force level and an acceptable crush initiation force, i.e. one that can be withstood by the backup structure. Additionally, crush debris from such tubes was found to neither contain objectionable sharp brittle splinters nor pose a health risk. Displacement average values of dynamic axial crush force ranged from 11.88 to 26.51 kN and values of SEA (specific energy absorption) ranged between 10.42 and 22.44 kJ/kg. In terms of parameter effects, the fiber type and reinforcement architecture were found to be capable of more than doubling/halving the dynamic axial crush force and SEA.

Dynamic Axial Crush Tests of Roll Wrapped Composite Tubes: Plug vs. Non-Plug Crush Initiators

2005 ◽  
Author(s):  
Alan L. Browne ◽  
Nancy L. Johnson
Keyword(s):  
Automotive Industry ◽  
Low Cost ◽  
High Volume ◽  
Longitudinal Axis ◽  
Free Flight ◽  
Composite Tubes ◽  
Fundamental Study ◽  
Average Value ◽  
Axial Crush ◽  
Zero Radius

This paper discusses the effects of the method of crush initiation on the dynamic axial crush response of roll wrapped composite tubes. This constitutes a portion of a successful fundamental study conducted at GM R&D of the dynamic axial crush of automotive rail-sized composite tubes reinforced variously with carbon fiber, Kevlar® and hybrid combinations of the two, and manufactured using roll wrapping techniques suitable for the low cost high volume needs of the automotive industry. All tubes were manufactured using roll wrapping from multiple layers of uni-directional thermoset prepreg with the uni-directional fabric plies being oriented at ± 15° with respect to the longitudinal axis of the tube. A total of 21 dynamic axial crush tests were conducted using a free flight drop tower facility. Tests spanned a range of tube geometries — circular and square with different wall and cross section dimensions with cored and uncored walls and differing numbers of plies — and a range of drop heights/impact velocities and drop masses. A general finding was that stable and progressive crush occurred at acceptable load levels in all of the roll-wrapped tubes that were tested for all methods of crush initiation that were considered — a 45° lead end bevel either alone, with a zero radius plug-type crush initiator, or with a 12.7 mm radius plug. The method of crush initiation was, however, found to be capable of producing major differences in the crush initiation force Fp, the displacement average crush force Fav(D), the specific energy absorption SEA, and the crush morphology. As examples, both the displacement average value of dynamic axial crush force and the value of SEA were changed by as much as a factor of eight by the method of crush initiation.

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