An investigation on rate sensitivity of energy absorption characteristic during tensile deformation with pre-cracked thin specimens made of TRIP steel by finite element analysis and experiment

2018 ◽  
Vol 2018.56 (0) ◽  
pp. 207
Author(s):  
Shiguma YOSHIDA ◽  
Ryusuke MAENAKA ◽  
Yuya OONISH ◽  
Takeshi IWAMOTO
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Absorption ◽  
Trip Steel ◽  
Tensile Deformation ◽  
Rate Sensitivity ◽  
Absorption Characteristic ◽  
Element Analysis

The equivalent method of double V-wing honeycombs on the in-plane dynamic impact

2021 ◽  
pp. 073168442199086
Author(s):  
Yunfei Qu ◽  
Dian Wang ◽  
Hongye Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Energy Absorption ◽  
Width Ratio ◽  
Size Factor ◽  
Dynamic Impact ◽  
Element Analysis ◽  
Equivalent Method

The double V-wing honeycomb can be applied in many fields because of its lower mass and higher performance. In this study, the volume, in-plane elastic modulus and unit cell area of the double V-wing honeycomb were analytically derived, which became parts of the theoretical basis of the novel equivalent method. Based on mass, plateau load, in-plane elastic modulus, compression strain and energy absorption of the double V-wing honeycomb, a novel equivalent method mapping relationship between the thickness–width ratio and the basic parameters was established. The various size factor of the equivalent honeycomb model was denoted as n and constructed by the explicit finite element analysis method. The mechanical properties and energy absorption performance for equivalent honeycombs were investigated and compared with hexagonal honeycombs under dynamic impact. Numerical results showed a well coincidence for each honeycomb under dynamic impact before 0.009 s. Honeycombs with the same thickness–width ratio had similar mechanical properties and energy absorption characteristics. The equivalent method was verified by theoretical analysis, finite element analysis and experimental testing. Equivalent honeycombs exceeded the initial honeycomb in performance efficiency. Improvement of performance and weight loss reached 173.9% and 13.3% to the initial honeycomb. The double V-wing honeycomb possessed stronger impact resistance and better load-bearing capacity than the hexagonal honeycomb under impact in this study. The equivalent method could be applied to select the optimum honeycomb based on requirements and improve the efficiency of the double V-wing honeycomb.

Mechanical Design, Additive Manufacturing, and Performance of Equal Volume Metamaterials

2021 ◽  
Author(s):  
Richárd Horváth ◽  
Vendel Barth ◽  
Viktor Gonda ◽  
Mihály Réger ◽  
Imre Felde
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Absorption ◽  
Mechanical Design ◽  
Area Under The Curve ◽  
Cell Number ◽  
Element Analysis ◽  
Cross Sectional ◽  
Unit Cells ◽  
And Performance

Abstract In this paper, we study the energy absorption of metamaterials composed of unit cells whose special geometry makes the cross-sectional area and the volume of the bodies generated from them constant (for the same enclosing box dimensions). After a parametric description of such special geometries, we analyzed by finite element analysis the deformation of the metamaterials we have designed during compression. We 3D printed the designed metamaterials from plastic to subject them to real compression. The results of the finite element analysis were compared with the real compaction results. Then, for each test specimen, we plotted its compaction curve. By fitting a polynomial to the compaction curves and integrating it (area under the curve), the energy absorption of the samples can be obtained. As a result of these investigations, we drew a conclusion about the relationship between energy absorption and cell number.

Prediction of Microstructure During High Temperature Forming of Ti-6Al-4V Alloy

2004 ◽  
Vol 449-452 ◽  
pp. 189-192 ◽  
Author(s):  
You Hwan Lee ◽  
T.J. Shin ◽  
Jong Taek Yeom ◽  
Nho Kwang Park ◽  
S.S. Hong ◽  
...  
Keyword(s):  
Activation Energy ◽  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Flow Stress ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Element Analysis ◽  
Strain Data ◽  
Final Microstructure

Prediction of final microstructures after high temperature forming of Ti-6Al-4V alloy was´attempted in this study. Using two typical microstructures, i.e., equiaxed and Widmanstätten microstructures, compression test was carried out up to the strain level of 0.6 at various temperatures (700 ~ 1100°C) and strain rates (10-4 ~ 102/s). From the flow stress-strain data, parameters such as strain rate sensitivity (m) and activation energy (Q) were calculated and used to establish constitutive equations for both microstructures. Then, finite element analysis was performed to predict the final microstructure of the deformed body, which was well accorded with the experimental results.

The Relationship between the Deformation of Spherical Indentation and Tensile Deformation

2016 ◽  
Vol 723 ◽  
pp. 363-368 ◽  
Author(s):  
P.M. Ogar ◽  
D.B. Gorokhov
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Deformation ◽  
Spherical Indentation ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Plastic Sphere ◽  
Plastic Displacement ◽  
Definition Of ◽  
The Relationship

The paper is devoted to the definition of the deformation during indentation of the sphere and its relationship with the tensile deformation. Proposed by different authors methods of determining the deformation of the contact are considered. The results of their researches may vary significantly. It is shown that in the last decade to determine the deformation, the finite element analysis taking into account the "sink-in/pile-up", i.e. an elastic sinking in and plastic piling up of the material on the edges of the indent during the indentation process is widely used. The purpose of this research is to determine the relationship between tension deformation and sphere indentation deformation with taking into account the last achievements in the field of finite-element modeling of elastic-plastic sphere indentation. It is considered two methods of determining of deformation. One uses the equation proposed by S.I. Bulychev, in which the Mayer’s index is determined from the results of finite element analysis. The second method use the energy concept of hardness. It is based on the assumption that within the range of uniform deformation during uniaxial tension and during sphere indentation, the same energy is consumed to the plastic displacement of the part of the material volume out of limits of initial volume. They have close results. The corresponding graphic relations are shown.

Energy Absorption Characteristics of a Carbon Fiber Composite Automobile Lower Rail: A Comparative Study

2015 ◽  
Author(s):  
Muhammad Ali ◽  
Khairul Alam ◽  
Eboreime Ohioma
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Energy Absorption ◽  
Reactive Force ◽  
Element Analysis ◽  
Cross Sectional Dimension ◽  
Force Displacement ◽  
Absorption Characteristics

Composite materials have emerged as promising materials in applications where low weight and high strengths are desired. Aerospace industry has been using composite materials for past several decades exploiting their characteristics of high strength to weight ratio over conventional homogenous materials. To provide a wider selection of materials for design optimization, and to develop lighter and stronger vehicles, automobile industries have been exploring the use of composites for a variety of components, assemblies, and structures. Composite materials offer an attractive alternate to traditional metals as designers have greater flexibility to optimize material and structural shapes according to functional requirements. However, any automotive structure or part constructed from composite materials must meet or exceed crashworthiness standards such as Federal Motor Vehicle Safety Standard (FMVSS) 208. Therefore, for a composite structure designed to support the integrity of the automotive structure and provide impact protection, it is imperative to understand the energy absorption characteristics of the candidate composite structures. In the present study, a detailed finite element analysis is presented to evaluate the energy absorbing characteristics of a carbon fiber reinforced polymer composite lower rail, a critical impact mitigation component in automotive chassis. For purposes of comparison, the analysis is repeated with equivalent aluminum and steel lower rails. The study was conducted using ABAQUS CZone module, finite element analysis software. The rail had a cross-sectional dimension of 62 mm (for each side), length of 457.2 mm, and a wall thickness of 3.016 mm. These values were extracted from automobile chassis manufacturer’s catalog. The rail was impacted by a rigid plate of mass 1 tonne (to mimic a vehicle of 1000 Kg gross weight) with an impact velocity of 35 mph (15646.4 mm/s), which is 5 mph over the FMVSS 208 standard, along its axis. The simulation results show that the composite rail crushes in a continuous manner under impact load (in contrast to a folding collapse deformation mode in aluminum and steel rails) which generates force-displacement curve with invariable crushing reactive force for the most part of the crushing stroke. The energy curves obtained from reactive force-displacement graphs show that the composite rail absorbs 240% and 231% more energy per unit mass as compared to aluminum and steel rails. This shows a significant performance enhancement over equivalent traditional metal (aluminum and steel) structures and suggests that composite materials in conjunction with cellular materials/configurations have a tremendous potential to improve crashworthiness of automobiles while offering opportunities of substantial weight reductions.

scholarly journals Micromechanical approaches to understand dwell fatigue: from titanium a-b microstructures to disc thermal alleviation

2020 ◽  
Vol 321 ◽  
pp. 04004
Author(s):  
Zebang Zheng ◽  
Zhen Zhang ◽  
Ben Britton ◽  
Fionn Dunne
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rate Sensitivity ◽  
Phase Slip ◽  
Element Analysis ◽  
Crystal Plasticity Finite Element ◽  
Ti Alloys ◽  
Dwell Fatigue ◽  
Polycrystal Plasticity

Micro-pillar tests on α and α-β colony Ti alloys in combination with crystal plasticity finite element analysis has enabled the extraction of a and b phase slip strength and rate sensitivity properties. Faithfully representative α-β microstructure polycrystal plasticity models have then been established in order to investigate dwell fatigue in isothermal rig test behaviour and anisothermal thermomechanical flight loading conditions. The role of thermal alleviation in diminishing dwell sensitivity has been demonstrated.

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