Development of Adaptable CFRP Energy Absorbers for Car Crashes

Schmidová, Nikola; Zavřelová, Tereza; Vašíček, Michal; Zavadil, Filip; Růžička, Milan; Rund, Martin

doi:10.1016/j.matpr.2018.08.152

Cited by 8 publications

(5 citation statements)

References 4 publications

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“…Carbon fiber reinforced polymer (CFRP), a novel composite with high strength/modulus to weight, fatigue resistance, excellent corrosion resistance, and designability [ 1 , 2 , 3 ], has been widely applied to important military and civilian fields [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ] of aerospace, wind turbine, high-end cars, construction, etc. However, thin-walled structures of CFRP composite manufactured by 2D fiber fabrics are relatively weaker in the epoxy adhesive layer and in the thickness direction in contrast to those homogeneous materials that are isotropic or identical in all directions, and these typically result in interfacial cracking and delamination, thus causing premature failures under external complex loads [ 11 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites

et al. 2023

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This study employed novel joint treatments to strengthen the carbon fiber reinforced polymer (CFRP) composites. Vertically aligned carbon nanotubes (VACNTs) were prepared in situ on the catalyst-treated CF surface via the chemical vapor deposition (CVD) method, intertwining into three-dimensional fiber-nets and fully surrounding CF to form an integrated structure. The resin pre-coating (RPC) technique was further used to guide diluted epoxy resin (without hardener) to flow into nanoscale and submicron spaces to eliminate void defects at the root of VACNTs. Three-point bending testing results showed the “growing CNTs and RPC”-treated CFRP composites yielded the best flexural strength, a 27.1% improvement over the specimens without treatment, while the failure modes indicated that the original delamination failure was changed into “flexural failure” with through-the-thickness crack propagation. In brief, growing VACNTs and RPC on the CF surface enabled toughening of the epoxy adhesive layer, reducing potential void defects and constructing the integrated quasi-Z-directional fiber bridging at the CF/epoxy interface for stronger CFRP composites. Therefore, the joint treatments of growing VACNTs in situ via the CVD method and RPC technique are very effective and have great potential in manufacturing high-strength CFRP composites for aerospace applications.

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Section: Introductionmentioning

confidence: 99%

Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites

et al. 2023

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“…In the event of a motor vehicle crash, the kinetic energy of the collision is in part transferred to vehicle occupants and passengers, who may suffer from injury if the energy exceeds a certain threshold [8,9], and the injury severity increases as the transferred kinetic energy increases [10], assuming other factors remain constant. The deformation and damage of the vehicle body to absorb kinetic energy have been crucial aspects of the passive safety of a vehicle [11]. The energy absorption has been achieved from the perspective of vehicle design (engine hood hinges [12]), geometric profile (circular tubes [13]), and material science (e.g., epoxy-based composite [14], magnesium alloy [15]).…”

Section: Energy and Motor Vehicle Crashesmentioning

confidence: 99%

Approximation Framework of Embodied Energy of Safety: Insights and Analysis

2020

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Transportation safety, as a critical component of an efficient and reliable transportation system, has been extensively studied with respect to societal economic impacts by transportation agencies and policy officials. However, the embodied energy impact of safety, other than induced congestion, is lacking in studies. This research proposes an energy equivalence of safety (EES) framework to provide a holistic view of the long-term energy and fuel consequences of motor vehicle crashes, incorporating both induced congestion and impacts from lost human productivity resulting from injury and fatal accidents and the energy content resulting from all consequences and activities from a crash. The method utilizes a ratio of gross domestic product (GDP) to national energy consumed in a framework that bridges the gap between safety and energy, leveraging extensive studies of the economic impact of motor vehicle crashes. The energy costs per fatal, injury, and property-damage-only (PDO) crashes in gasoline gallon equivalent (GGE) in 2017 were found to be 200,259, 4442, and 439, respectively, which are significantly greater than impacts from induced congestion alone. The results from the motor vehicle crash data show a decreasing trend of EES per crash type from 2010 and 2017, due primarily in part to a decreasing ratio of total energy consumed to GDP over those years. In addition to the temporal analysis, we conducted a spatial analysis addressing national-, state-, and local-level EES comparisons by using the proposed framework, illustrating its applicability.

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“…VPP show potential for other commercial applications, such as active collision energy absorbers [19,27,31,42], but the main problem is that prototyping has overtaken basic research and modeling. It can be stated with great certainty that, without defined material properties and the proper modeling methodology, it is not possible to design and build a real engineering facility of high quality.…”

Section: Introductionmentioning

confidence: 99%

Temperature and strain rate effects of jammed granular systems: experiments and modelling

2021

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Jammed granular systems, also known as vacuum packed particles (VPP), have begun to compete with the well commercialized group of smart structures already widely applied in various fields of industry, mainly in civil and mechanical engineering. However, the engineering applications of VPP are far ahead of the mathematical description of the complex mechanical mechanisms observed in these unconventional structures. As their wider commercialization is hindered by this gap, in the paper the authors consider experimental investigations of granular systems, mainly focusing on the mechanical responses that take place under various temperature and strain rate conditions. To capture the nonlinear behavior of jammed granular systems, a constitutive model constituting an extension of the Johnson–Cook model was developed and is presented. green The extended and modified constitutive model for VPP proposed in the paper could be implemented in the future into a commercial Finite Element Analysis code, making it possible to carry out fast and reliable numerical simulations.

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Development of Adaptable CFRP Energy Absorbers for Car Crashes

Cited by 8 publications

References 4 publications

Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites

Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites

Approximation Framework of Embodied Energy of Safety: Insights and Analysis

Temperature and strain rate effects of jammed granular systems: experiments and modelling

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