저자명 M. Kim and H. Huh 
Name WCCM2016 
Place WCCM2016 
Year 2016 
This paper is concerned with the hardening behavior of sheet metals at intermediate strain rates ranging from 0.001 s-1 to 100 s-1 with respect to the pre-strain in order to propose a new flow stress model for a pre-strained material. Most members of an auto-body are made of mild steels or advanced high strength steels(AHSS) fabricated by the sheet metal forming process. During the process, the flow stress of the sheet metals are changed with the plastic strain as well as residual stress and consequently the tensile properties of the sheet metals are also changed. A new design of a device to impose the pre-strain was developed to investigate the hardening behavior of the sheet metals considering the pre-strain and the specimens were obtained from the sheet metals with SPCC(CQ) and DP590(DP) for outer and inner members of an auto-body. The specimens were prepared with the pre-strain of 5 % and 10 % using tensile testing machines and the pre-straining device. The Instron 5583 and a high speed material testing machine (HSMTM) were utilized at the quasi-static state of 0.001 s-1 and the intermediate strain rates ranging from 1 s-1 to 100 s-1 respectively. The experimental results demonstrate that the stress–strain curves at the strain rate of 0.001 s-1 for SPCC and DP590 pre-strained by 5 % and 10 % traced the original stress–strain curve without the pre-strain, following a classical conjecture that the flow stress of a material follows the unique stress–strain curve. The results also reveal that the hardening behavior of SPCC and DP590 were noticeably influenced by the pre-strain with stress overshooting when the strain rate is over 1 s-1 and the flow stress as well as the ultimate tensile strength increased due to the pre-strains consequently. For an accurate crash analysis of an auto-body, the correct material properties should be utilized for the numerical simulation with the stress–strain relation depending on the strain rate and the amount of pre-strain.
번호 제목 저자명 날짜 조회 수
176 TOPOLOGY OPTIMIZATION OF PLASTIC STRUCTURES USING FINITE ELEMENT LIMIT ANALYSIS file Jongsup Lee, Hoon Huh  2009.07.30 7713
175 Compressive Characteristics of PBX Simulant with the Variation of the Strain Rate file Chunghee Park, Sehwan...  2012.09.21 7637
174 A Phenomenological energy-based Model for PBX Simulants Considering the Mullins Effect file Kee Sun Yeom Sehwan J...  2013.02.06 7471
173 Dynamic Failure Characteristics of Electric Resistance Spot Welds in DP Steel Sheets [2] file Jiwoong Ha Hoon Huh J...  2012.12.10 7037
172 Variational Time Integrators for Handling Discontinuous Interfaces in Solids file S. J. Lim S. S. Cho H...  2012.03.20 6482
171 Buffer Stopper Using Progressive Compression Process for Crash Energy Absorption of a Railway Vehicle Kwanghyun Ahn Hoon Hu...  2011.12.22 6408
170 MECHANICAL CHARACTERISTICS OF PBX SIMULANT CONSIDERING STRAIN RATE EFFECT file Chunghee Park Sehwan ...  2011.07.04 6367
169 Effect of helicity on the buckling behavior of single-wall carbon nanotubes file Jeehyang Huh Hoon Huh  2008.12.15 6284
168 Evaluation of Dynamic Hardening Models for Metallic Materials at Wide Range of Strain Rates file Hoon Huh Kwanghyun Ah...  2012.09.26 6141
167 Micro-Tensile Tests of Aluminum Thin Foil with the Variation of Strain Rate file J.B. Kwon J. Huh H. H...  2012.06.19 6090
166 Material Properties of PBX Simulant Considering Strain Rate Effect file Chunghee Park Sehwan ...  2010.12.22 5930
165 Development of Buffer Stopper Using Progressive Compression Process for Crash Energy Absorption of a Railway Vehicle file Kwanghyun Ahn Hoon Hu...  2012.12.10 5866
164 Quantification of Material Properties of Structural Materials for Warhead at Various Strain Rates file Kwanghyun Ahn Hoon Hu...  2012.09.26 5834
163 Effect of Strain Rate on the Material Characteristics of a Fragment-Simulating Warhead and an Armor Plate file Jiwoong Ha Hoon Huh K...  2012.06.27 5815
162 Material Behaviors of PBX Simulant with Various Strain Rates [1] file Chunghee Park Sehwan ...  2013.01.08 5776
161 Ductile fracture of dual phase steel: mechanisms, modeling, prediction and prospective applications file Yanshan Lou, Hoon Huh  2013.02.01 5740
160 Effect of the Yield Stress and r-value Distribution on the Earing Profile of Cup Drawing with Yld2000-2d Yield Function file Yanshan Lou Gihyun Ba...  2010.07.14 5554
159 Prediction of forming limit diagrams of DP590 steel based on the M-K model with experimental verification file Yanshan Lou Seokbong ...  2010.12.27 5512
158 Development and investigation of nonlinear shell elements with drilling degree of freedom file H. W. Lee H. Huh  2005.11.29 5509
157 Rate-dependent two-surface model for cyclic hardening behaviour of advanced high strength steel sheets file Jeehyang HUh Hoon Huh...  2012.11.06 5424