Crash energy absorbing composite subfloor structure. Structures and materials with functionally graded properties exhibit much better crashworthiness. An overview of the course and an introduction to the topic is given in this session. In order to analyse the energy absorbing capabilities of longerons under axial compression loading and to evaluate the influence of longerons geometrical characteristics and materials degradation on the vehicles safety experimental investigations and numerical calculations were performed. Jun 17, 2015 new energy absorbing structure to better withstand impact 17 june 2015 researchers in the cockrell school of engineering at the university of texas at austin have developed a groundbreaking new energy absorbing structure to better withstand blunt and ballistic impact. Energy absorption in polymer composite materials for automotive crashworthiness george c. Understanding of energy absorption of structures and materials is important in calculating the damage to structures caused by accidental collision, assessing the residual strength of structures. Pdf energy absorption of a helicoidal bistable structure. Those materials were chosen because of their high thermal shock resistance or their great capability in energy absorption. Impact mechanics and highenergy absorbing materials. Energy absorption of structures and materials description. Mechanical properties and performance of materials samples of engineering materials are subjected to a wide variety of mechanical tests to measure their strength, elastic constants, and other material properties as well as their performance under a variety of actual use conditions and environments. The energy absorption and post crushing integrity of hybrid composite tubes were not significantly better than that of the single material tubes.
Energy absorption in polymer composite materials for. An energy absorption behaviour of foam filled structures. Design study of shape memory alloy honeycombs for energy absorption. Energy absorption properties of periodic and stochastic 3d. The energy absorption efficiency, plateau stress, peak stress of chiral structures with different ligament.
Side impact protection, racing car, energy absorption, sandwich composites, structures 1. Aug 22, 2012 27th structures, structural dynamics and materials conference august 2012 development of a test method for composite materials energy absorption. This important study focuses on the way in which structures and materials can be best designed to absorb kinetic energy in a controllable and predictable. The model development philosophy included measurement of the mechanical properties of each material in the helmet, development and validation of fe models. Energy absorption and crush behavior of the layered. However, little work has been devoted to comparing energy absorption properties in different periodic three. The influence of different parameters on the material behavior of natural fiber reinforced plastic structures has been. Energy absorption of structures and materials semantic scholar. Mechanical properties and energy absorption of heterogeneous and. We consider the theoretical condition for perfect light absorption in the 2d material with the structure shown in figure 1a. Proceedings of the asme 2011 conference on smart materials, adaptive structures and intelligent systems. Either the energy is absorbed directly by the aircraft structure by ductile deformation through the selection of appropriate skin materials e. Among these energy absorption mechanisms, the attention of this book will be mainly focused on energy absorption due to plastic deformation of structures and materials, because this is the most effective mechanism for absorbing energy in ductile materials e.
Understanding of energy absorption of structures and materials is important in calculating the damage to structures caused by accidental collision, assessing the residual strength of structures after initial damage and in designing. Energy absorption is defined as the surface below the loaddisplacement curve. Jacob material science and engineering department university of tennessee, knoxville 434 dougherty engineering knoxville, tn 37996 usa john f. Energy absorption of structures and materials 1st edition. Lattice structures offer the potential to relatively easily engineer specific mesoscale properties cell level, to produce desirable macroscale material properties for a wide variety of engineering applications including wave filters, blast and impact protection systems, thermal insulation, structural aircraft and vehicle components, and body implants. The inventors at uci have designed a shape reconfigurable material whose qualities far surpass other state of the art materials. Silk lattice structures from unidirectional silk fiber. This important new study focuses on the way in which structures and. Tables of xray mass attenuation coefficients and mass. The triply periodic minimal surface tpms method is a novel approach for lattice design in a range of fields, such as impact protection and structural lightweighting. In this work, by combining experimental and numerical methods, we investigate the compressive behavior and energy absorption of lattices made through the stereolithography apparatus process. Materials free fulltext energy absorption capacity in. Us8579073b2 acoustic energy absorption metamaterials. Maysam gorji bandpay massachusetts institute of technology mit, impact and crashworthiness laboratory, usa.
Design and build structural tubes of various configurations using the above materials and perform quasistatic and dynamic crush tests to assess their energy absorption. Natural silk fibers and their composites have shown great energy absorption potential and impact resistance. Active application number us687,436 other versions us203979a1. Characterize such materials by measuring their mechanical properties. Can generate energy absorption diagrams from data, or use models for foam. Energy absorption of crashworthy structure for rolling stock of a railway. Nanohoneycomb structures for optimal energy absorption. In this paper, we used the tpms formula to rapidly and accurately generate the most common lattice structure, named the body centered cubic bcc structure, with certain volume fractions. Research directions on graded structures and materials are discussed. Plastic deformation, failure and energy absorption of sandwich. Introduction side impact accidents may result in severe injuries to the vehicle occupants. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. Shape reconfigurable materials and structures for shape.
Energy absorption of structures and materials by g lu. For simplicity, we assume that all layers except the 2d material is. This important new study focuses on the way in which structures and materials can be designed to absorb kinetic energy in a controllable and predictable manner. Energy absorption of structures and materials request pdf.
Herein, lattice structures are designed and fabricated from silk. Energy absorption is the area under a stressstrain curve and thus highly. Improved mechanical properties and energy absorption of bcc. The crash energy absorption of the vehicles front structures.
Energy absorption of structures and materials g lu, t x. Energy absorption an overview sciencedirect topics. Particularly, the practical research for the relationship between the specific energy absorption and bulk modulus of a 3d periodic cellular materials is the main concern. The prediction of damage to structures caused by accidental collision whether to automobiles, offshore installations or simply the packaging around an electrical appliance is a crucial factor in their design. The study of natural fiber reinforcement composite structures has focused the attention of the automobile industry due to the new regulation in relation to the recyclability and the reusability of the materials preserving and or improving the mechanical characteristics. During energy absorption, the materials need to be able to maintain a gradual deterioration in the load profile 4. The knowhow of energy absorption behavior is an important part for material option and design of energy absorbers, crashworthiness and failure assessment of structures subjected to collisions.
Contribution of energyabsorbing structures to head. Asme 2011 conference on smart materials, adaptive structures and intelligent systems. Sep 25, 2019 lattice structures have numerous outstanding characteristics, such as light weight, high strength, excellent shock resistance, and highly efficient heat dissipation. The energy absorbing performance of two types of lattice structure, namely, octagonal and kelvin lattices, is investigated. Energy absorption capability and crashworthiness of composite. This important study focuses on the way in which structures and materials can be best designed to absorb kinetic energy in a controllable and predictable manner. Apr 18, 2019 the design freedom to create complex shapes and parts is one of the major benefits offered by the 3d printing manufacturing process. Energy absorption of structures and materials energy absorption of structures and materials guoxing lu and tongxi yu.
International conference on advances in manufacturing and materials engineering. Investigation of highvelocity projectile penetrating. Design study of shape memory alloy honeycombs for energy. The investigated models are reinforced using different layers combinations of several materials such as ceramics, fiber composite, polymer and metal. Moreover, irregular cellular structures showed to have energy absorption similar. The general principles involved in designing structures and selecting materials for the purpose of energy absorption are also discussed. Energy absorption in lattice structures in dynamics. Performances of graded structures can be further improved by optimized design. Most side impacts can be classified into two types, cartobroadobject and. Energy absorption of structures and materials 1st edition elsevier. The produced materials exhibit increased strength and energy absorption capability, which are critical for use as an impact absorber or vibration dampener. The average load is identified as one of the determination parameters of absorbed energy capability based on the definition of energy absorption and peak load value, which was attained in the first step of a quasistatic test. Energy absorption of a helicoidal bistable structure article pdf available in journal of mechanics of materials and structures 52. Gre and gle tubes failed in a brittle mode and had negligible post crushing integrity, whereas the ke tubes failed in an accordian buckling mode similar to the aluminum tubes.
New energyabsorbing structure to better withstand impact. Spectral absorption control of femtosecond lasertreated. Energy absorption of structures and materials sciencedirect. The aim of this study is to utilize this advantage to tailor and optimize cellular materials for impact energy absorbing applications. Pdf impact energy absorption performances of ordinary and. The maximum loads applicable to the ac structure and overhead stowage compartment ohsc could be reduced using the described energy absorbing force limiters. An investigation into energy absorption requires an understanding of materials engineering, structural mechanics, the theory of plasticity and impact dynamics. During the frontal crash the longerons absorb most energy of all vehicles construction elements. Predictive technology development and crash energy management. Understanding of energy absorption of structures and materials is important in calculating the damage to structures caused by accidental collision, assessing the residual strength of structures after initial damage and in designing packaging to protect its contents in the event of impact. Article information, pdf download for plastic deformation, failure and energy absorption of. Energy absorption of structures and materials, international. Although structural collapse occurred by a fracture failure mode, the specific energy absorption was higher than that of high strength metal tubes which col lapsed by buckling, over a wide range of tube geometries td ratios, provided that the correct trigger mechanism was used to initiate the failure.
Aug 01, 2004 energy absorption of structures and materials energy absorption of structures and materials wierzbicki, t 20040801 00. Relationship between mechanicalproperty and energy. Angleselective perfect absorption with twodimensional. Fellers professor material science and engineering department university of tennessee, knoxville 608 dougherty. Energy absorbing materials and structures when it comes to energy absorption in a dynamic load case, two general options are possible for structural design and structural performance. Design and evaluation of 3d printed polymeric cellular. Purchase energy absorption of structures and materials 1st edition. Pdf impact mechanics and highenergy absorbing materials. Energy absorption of structures and materials pdf free.
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