Over the past several decades, a noticeable amount of research efforts has been directed to minimising injuries and death to people inside a structure that is subjected to an impact loading.
...Thin-walled (TW) tubular components have been widely employed in energy absorbing structures to alleviate the detrimental effects of an impact loading during a collision event and thus enhance the crashworthiness performance of a structure.
Comprehensive knowledge of the material properties and the structural behaviour of various TW components under various loading conditions is essential for designing an effective energy absorbing system.
In this paper, based on a broad survey of the literature, a comprehensive overview of the recent developments in the area of crashworthiness performance of TW tubes is given with a special focus on the topics that emerged in the last ten years such as crashworthiness optimisation design and energy absorbing responses of unconventional TW components including multi-cells tubes, functionally graded thickness tubes and functionally graded foam filled tubes.
Due to the huge number of studies that analysed and assessed the energy absorption behaviour of various TW components, this paper presents only a review of the crashworthiness behaviour of the components that can be used in vehicles structures including hollow and foam-filled TW tubes under lateral, axial, oblique and bending loading.
•Researches on energy absorption behaviour of hollow tubes are reviewed.•An overview is given on the crashworthiness behaviour of foam-filled tubes.•Studies on the crashworthiness design and optimisation are summarised.•Crashworthiness topics that require further developments are identified.
The automotive industry faces many challenges, including increased global competition, the need for higher-performance vehicles, a reduction in costs and tighter environmental and safety ...requirements. The materials used in automotive engineering play key roles in overcoming these issues: ultimately lighter materials mean lighter vehicles and lower emissions. Composites are being used increasingly in the automotive industry due to their strength, quality and light weight. Advanced Composite Materials for Automotive Applications: Structural Integrity and Crashworthiness provides a comprehensive explanation of how advanced composite materials, including FRPs, reinforced thermoplastics, carbon-based composites and many others, are designed, processed and utilized in vehicles. It includes technical explanations of composite materials in vehicle design and analysis and covers all phases of composite design, modelling, testing and failure analysis. It also sheds light on the performance of existing materials including carbon composites and future developments in automotive material technology which work towards reducing the weight of the vehicle structure. Key features: * Chapters written by world-renowned authors and experts in their own fields * Includes detailed case studies and examples covering all aspects of composite materials and their application in the automotive industries * Unique topic integration between the impact, crash, failure, damage, analysis and modelling of composites * Presents the state of the art in composite materials and their application in the automotive industry * Integrates theory and practice in the fields of composite materials and automotive engineering * Considers energy efficiency and environmental implications Advanced Composite Materials for Automotive Applications: Structural Integrity and Crashworthiness is a comprehensive reference for those working with composite materials in both academia and industry, and is also a useful source of information for those considering using composites in automotive applications in the future.
Hierarchical materials are widely observed in nature, and have been credited with superior mechanical properties and weight efficiency. In the present work, fractal-appearing self-similar regular ...hexagonal hierarchical honeycombs (HHHs) are constructed by iteratively replacing each three-edge vertex of a base hexagonal network with a smaller regular hexagon up to second order. The cell wall thickness is adjusted so that the two fractal configurations have identical density as the base honeycomb. To investigate the out-of-plane crashworthiness of this new class of hexagonal hierarchical honeycomb concept, finite element modeling is carried out and validated using experiment results. By comparing the results of three traditional corrugated hexagonal honeycombs (0th order HHH) with those pertinent to two novel 1st and 2nd order HHHs, it can be concluded that hierarchical organization of different cells can enhance the material/strength distribution across the network, resulting in improved crush strength and crush force efficiency. In addition, parametric studies are carried out to explore two further strategies to improve out-of-plane crashworthiness by altering the material distribution, namely changing relative cell sizes and cell wall thickness. The results suggest that further improvement can be realized through optimum designs of the fractal geometries.
Body repairs are often based not so much on procedures as on the experience of the people who perform these repairs. The problem is that heat repairs change the internal structure of the vehicle's ...skin. When obtaining homologation, manufacturers must prove the specific strength of the materials during crash tests. During a bodywork repair, these parameters may change, and after the repair, there is no obligation to check the strength parameters of a specific element or system. By interfering with the structure, we cannot be sure that we still maintain an appropriate level of security. Therefore, during further tests, together with a team from the Bydgoszcz University of Technology, we plan to check the strength parameters of the vehicle's skin after repair. And what impact on the structure of the material is the duration of individual stages of sheet metal work, the intensity of the current and the temperature to which the material is heated in order to optimize the parameters and increase the level of safety of users.
Crashworthiness is the ability of civil aircraft fuselage structure and internal systems to maximum protect the occupants’ safety in a crash or emergency landing event, and is an important embodiment ...of the civil aircraft safety, which can determine the occupant survivability to a certain extent. The crashworthiness is dominated by the crash response characteristics of typical fuselage section (including occupant/seat restraint system), and the crashworthiness evaluation mainly includes fuselage structural response evaluation and occupant injury evaluation. Firstly, the crashworthiness requirements are sorted out according to the Airworthiness Standards of transport category airplanes and Special Conditions, and the research work on drop tests and crashworthiness numerical simulation of fuselage section are gathered. Then, the failure of typical skin-stringer-frame structures and fuselage section are analyzed, and the crash safety evaluation criteria are summarized. After that, the impact tolerance of various parts of human (head, neck, thoracic, spine, abdomen, extremity) and the occupant injury evaluation criteria are summarized. In addition, the crashworthiness design principles and design methods of fuselage section are outlined for occupant survivability. Finally, the crashworthiness evaluation under different crash factors and conditions (impact velocity, impact ground, cargo loading and aircraft wing position) are summed up, and the aircraft crashworthiness is comprehensively evaluated through integrating the survivable volume, the retention strength, the occupant injury and the emergency evacuation, and the crashworthiness evaluation process is outlined. This article is intended as a comprehensive literature review of crashworthiness design and evaluation of fuselage structure for occupant survivability.
This work is a logical continuation of studies presented in the author’s previous publications 1,2,3 on establishing the analytical application features of the developed methodology for simulating ...natural tests in accordance with UN/ECE Regulation No. 66. 4, as well as evaluating the identity between calculated and experimental results of checking the reserve of cabin space. The relevance of the proposed methodology is primarily related to the need to comply with the requirements of the current Regulation regarding the level of passive safety of passengers in the cabin during the certification of buses: a real-life approach to testing is conducted with a series of crash tests, which lead to the inevitable destruction of the bus body frame. We would like to remind that the specific weight of the body cost in the total cost of the bus, depending on its type, can reach up to 50% of its price, which leads to exorbitant costs during the certification of road prototypes before the start of their commercial operation.
•Several bio-inspired hexagonal tubes and their hierarchical structures were developed as the potential choice of high-performance energy absorption device;.•The mechanism of improving energy ...absorption ability with reinforcement was clearly revealed, the formation of lobes is accompanied by enormous interaction of thin walls.•Structural effect and geometric effect were discussed between different reinforced patterns. Self-similar hierarchical design can greatly increase the stability of the axial collapse process, while the lattice enhancement design shows higher SEA. Double filled hexagonal tube (DFHT) were recommended as an optimal geometry.•Detailed explanations were theoretically given with representative specimens for the reason of improvement in mechanical performance.
Bio-inspired conception is prevailing in structure design due to its mechanical promotion. In this study, crashworthiness analyses of twelve patterns of hexagonal prismatic tubes were numerically investigated by means of Finite Element method, including original hexagonal tube (OHT), full triangular hexagonal tube (FTHT), internal clone hexagonal tube (ICHT), double filled hexagonal tube (DFHT) and their reinforced hierarchical structures. Key crashworthiness indexes of different structures were compared with each other in detail. Corresponding formulas to predict the mechanical performance were derived representatively. As confirmed by both theoretical solutions and numerical results, the energy absorption capacities and deformation modes of the bio-inspired hexagonal prismatic tubes are superior to those of the original ones. Although they contribute substantially to the improvement of energy absorption ability, the different reinforcement ways show their different merits. Self-similar hierarchical designs can greatly increase the stability of the axial collapse process. While the lattice enhancement designs show higher SEA. All achievements in this study provide significant guidelines in the reinforcement design of lightweight structures.
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