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Viewing 151 to 180 of 20079
2015-04-14
Journal Article
2015-01-1754
Wei-Jen Lai, Jwo Pan
Abstract In this paper, the analytical stress intensity factor and J integral solutions for welds in lap-shear specimens of two dissimilar sheets based on the beam bending theory are first reviewed. The solutions are then presented in the normalized forms. Next, two-dimensional finite element analyses were selectively conducted to validate the analytical solutions based on the beam bending theory. The interface crack parameters, the stress intensity factor solutions, and the J integral solutions for welds in lap-shear specimens of different combinations of steel, aluminum, and magnesium, and the combination of aluminum and copper sheets of different thickness ratios are then presented for convenient fracture and fatigue analyses. The transition thickness ratios for critical crack locations for different combinations of dissimilar materials are then determined from the analytical solutions.
2015-04-14
Technical Paper
2015-01-1736
Justin Cartwright, Ahmet Selamet, Robert Wade, Keith Miazgowicz, Clayton Sloss
Abstract The heat rejection rates and skin temperatures of a liquid cooled exhaust manifold on a 3.5 L Gasoline Turbocharged Direct Injection (GTDI) engine are determined experimentally using an external cooling circuit, which is capable of controlling the manifold coolant inlet temperature, outlet pressure, and flow rate. The manifold is equipped with a jacket that surrounds the collector region and is cooled with an aqueous solution of ethylene-glycol-based antifreeze to reduce skin temperatures. Results were obtained by sweeping the manifold coolant flow rate from 2.0 to 0.2 gpm at 12 different engine operating points of increasing brake power up to 220 hp. The nominal coolant inlet temperature and outlet pressure were 85 °C and 13 psig, respectively. Data were collected under steady conditions and time averaged. For the majority of operating conditions, the manifold heat rejection rate is shown to be relatively insensitive to changes in manifold coolant flow rate.
2015-04-14
Technical Paper
2015-01-0459
Vesna Savic, Louis Hector, Hesham Ezzat, Anil Sachdev, James Quinn, Ronald Krupitzer, Xin Sun
Abstract This paper presents an overview of a four-year project focused on development of an integrated computational materials engineering (ICME) toolset for third generation advanced high-strength steels (3GAHSS). Following a brief look at ICME as an emerging discipline within the Materials Genome Initiative, technical tasks in the ICME project will be discussed. Specific aims of the individual tasks are multi-scale, microstructure-based material model development using state-of-the-art computational and experimental techniques, forming, toolset assembly, design optimization, integration and technical cost modeling. The integrated approach is initially illustrated using a 980MPa grade transformation induced plasticity (TRIP) steel, subject to a two-step quenching and partitioning (Q&P) heat treatment, as an example.
2015-04-14
Technical Paper
2015-01-0737
Sadegh Poozesh, Nelson Akafuah, Kozo Saito
Abstract Lack of a precise control over paint droplets released from current coating sprayers has motivated this study to develop an atomizer capable of generating a uniform flow of mono-dispersed droplets. In the current study, a numerical investigation based on CFD incorporating volume of fluid (VOF) multiphase model has been developed to capture the interface between air and paint phases for a typical atomizer equipped with piezoelectric actuator. Effects of inlet flow rate and actuator frequency on ejected droplets' characteristics, droplet diameter and their successive spacing are studied in detail. It will be shown that for a determined flow rate of paint, there is an optimum actuator frequency in which droplet size is minimum. Besides, there exists a direct relationship between the inlet paint velocity and obtained optimal actuator frequency.
2015-04-14
Technical Paper
2015-01-0531
Hiroyuki Yamashita, Hiroaki Ueno, Hiroyuki Nakai, Takahiro Higaki
Abstract When the strain is temporarily stopped during tensile testing of a metal, a stress relaxation phenomenon is known to occur whereby the stress diminishes with the passage of time. This phenomenon has been explained as the change of elastic strain into plastic strain. A technique was devised for deliberately causing strain dispersion to occur by applying the stress relaxation phenomenon during stamping. A new step motion that pause the die during forming was devised; it succeeded in modifying the deep-draw forming limit by a maximum of 40%. This new technique was verified through tensile and actual stamping tests. It was confirmed that the use of step motion causes the strain to disperse, thereby modifying the deep draw forming limit. The degree to which the forming limit is modified is dependent on the stop time and the temperature.
2015-04-14
Journal Article
2015-01-0530
Mikko Joonas Kähkönen, Emmanuel De Moor, John Speer, Grant Thomas
Abstract Quenching and partitioning (Q&P) is a novel heat treatment to produce third generation advanced high-strength steels (AHSS). The influence of carbon on mechanical properties of Q&P treated CMnSi-steels was studied using 0.3C-1.5Mn-1.5Si and 0.4C-1.5Mn-1.5Si alloys. Full austenitization followed by two-step Q&P treatments were conducted using varying partitioning times and a fixed partitioning temperature of 400 °C. The results were compared to literature data for 0.2C-1.6Mn-1.6Si, 0.2-3Mn-1.6Si and 0.3-3Mn-1.6Si Q&P treated steels. The comparison showed that increasing the carbon content from 0.2 to 0.4 wt pct increased the ultimate tensile strength by 140 MPa per 0.1 wt pct C up to 1611 MPa without significantly decreasing ductility for the partitioning conditions used. Increased alloy carbon content did not substantially increase the retained austenite fractions.
2015-04-14
Journal Article
2015-01-0519
Susumu Maeda, Atsushi Kobayashi, Yuichiro Shimizu, Masao Kanayama, Masato Yuya, Hideki Imataka
Abstract A new nitriding technology and material technology have been developed to increase the strength of microalloyed gears. The developed nitriding technology makes it possible to freely select the phase composition of the nitride compound layer by controlling the treatment atmosphere. The treatment environment is controlled to exclude sources of supply of [C], and H2 is applied as the carrier gas. This has made it possible to control the forward reaction that decomposes NH3, helping to enable the stable precipitation of γ′-phase, which offers excellent peeling resistance. A material optimized for the new nitriding technology was also developed. The new material is a low-carbon alloy steel that makes it possible to minimize the difference in hardness between the compound layer and the substrate directly below it, and is resistant to decline in internal hardness due to aging precipitation in the temperature range used in the nitriding treatment.
2015-04-14
Journal Article
2015-01-0518
Hirokuni Fuchigami
Abstract In this research, a new wire material made using surface-reforming heat treatment was developed in order to enhance the corrosion fatigue resistance of suspension springs. The aim of surface reforming is to improve hydrogen embrittlement characteristics through grain refinement and to improve crack propagation resistance by partial softening of hardness. The grain refinement method used an α'→γ reversed transformation by rapid short-term heating in repeated induction heating and quenching (R-IHQ) to refine the crystal grain size of SAE 9254 steel spring wire to 4 μm or less. In order to simultaneously improve the fatigue crack propagation characteristics, the possibility of reducing the hardness immediately below the spring surface layer was also examined. By applying contour hardening in the second IHQ cycle, a heat affected zone (HAZ) is obtained immediately below the surface.
2015-04-14
Technical Paper
2015-01-0524
Maniraj Perumal, Baskar Anthonysamy, Ashokkumar Sundaramoorthy
This method and its special process are particularly suited for the production of Porous free combustion chamber prototype aluminium cylinder head casting. Current methods for producing porous free combustion chamber are graphite coating and CI/Cu metal chill which are moderately effective in achieving porous free combustion chamber. However, these current methods have serious drawbacks like high rejections due to blow holes/gas porosity generated from graphite coating and fine porosity due to prolonged cooling because of slow rate of cooling while peak temperature of metal chills. The present work shows how this goal can be achieved in cylinder head casting of single cylinder high speed engine. Fundamental micro structural investigations are shown as well as the results of tensile tests, high temperature strength, corrosion behavior and static and dynamic component testing.
2015-04-14
Technical Paper
2015-01-0582
Deepak Ranjan Bhuyan, Sreekanth Netapalli, Sathya Dev, Soundarya Srinivasan
Abstract Springback prediction for stamped components is a challenging task for Automotive Industry. Automotive Manufacturers are working to reduce the springback effect of sheet metal stampings caused due to elastic behavior of materials with the help of changes to manufacturing process and part geometry. Recent development in Finite Element Analysis (FEA) studies made it possible for the industry to rely on stamping simulation. There is always a gap between the springback predicted from stamping simulation and the actual stamped part. Currently FEA techniques are trying to close this gap. The objective of this study is to minimize this gap using DFSS method for predicting the springback and optimizing the simulation parameters with the help of LS-Dyna FEM tool. The behavior of material with different simulation parameters has been studied in this paper and the ones that best correlate with actual data are identified.
2015-04-14
Technical Paper
2015-01-0551
Qiuren Chen, Haiding Guo, John V. Lasecki, John Hill, Xuming Su, John J. Bonnen
Abstract The fatigue strength and failure behavior of A5754-O adhesively bonded single lap joints by a hot-curing epoxy adhesive were investigated in this paper. The single lap joints tested include balanced substrate joints (meaning same thickness) and unbalanced substrate joints, involving combinations of different substrate thicknesses. Cyclic fatigue test results show that the fatigue strength of bonded joints increase with the increasing substrate thickness. SEM and Energy Dispersive X-ray (EDX) were employed to investigate the failure mode of the joints. Two fatigue failure modes, substrate failure and failure within the adhesive were found in the testing. The failure mode of the joint changes from cohesive failure to substrate failure as the axial load is decreased, which reveals a fatigue resistance competition between the adhesive layer and the aluminum substrate.
2015-04-14
Journal Article
2015-01-0537
Hong Tae Kang, Abolhassan Khosrovaneh, Xuming Su, Yung-Li Lee, Mingchao Guo, Chonghua Jiang, Zhen Li
Abstract Due to magnesium alloy's poor weldability, other joining techniques such as laser assisted self-piercing rivet (LSPR) are used for joining magnesium alloys. This research investigates the fatigue performance of LSPR for magnesium alloys including AZ31 and AM60. Tensile-shear and coach peel specimens for AZ31 and AM60 were fabricated and tested for understanding joint fatigue performance. A structural stress - life (S-N) method was used to develop the fatigue parameters from load-life test results. In order to validate this approach, test results from multijoint specimens were compared with the predicted fatigue results of these specimens using the structural stress method. The fatigue results predicted using the structural stress method correlate well with the test results.
2015-04-14
Technical Paper
2015-01-0545
Jeong Kyun Hong
Abstract As the automotive industry seeks to remove weight from vehicle chasses to meet increased fuel economy standards, it is increasingly turning to composites and aluminum. In spite of increasing demands for quality aluminum alloy spot welds that enable more fuel efficient automobiles, fatigue evaluation procedures for such welds are not well-established. This article discusses the results of an evaluation Battelle performed of the fatigue characteristics of aluminum alloy spot welds based on experimental data and observations from the literature. In comparison with spot welds in steel alloys, aluminum alloy spot welds exhibit several significant differences including a different hardness distribution at and around the weld, different fatigue failure modes, and more. The effectiveness and applicability of the Battelle structural stress-based simplified procedure for modeling and simulating automotive spot welds has previously been demonstrated by Battelle investigations.
2015-04-14
Journal Article
2015-01-0604
Jibrin Sule, Supriyo Ganguly
Abstract In a multi-pass weld, the development of residual stress to a large extent depends on the response of the weld metal, heat affected zone and parent material to complex thermo-mechanical cycles during welding. Previous investigations on this subject mostly focused on mechanical tensioning or heat treatment to modify the residual stress distribution in and around the weld. In this research, microstructural refinement with modification of residual stress state was attempted by applying post weld cold rolling followed by laser processing. The hardening of the weld metal was evaluated after welding, post weld cold rolling and post weld cold rolling followed by laser processing. The residual stress was determined non-destructively by using neutron diffraction. Hardness results showed evidence of plastic deformation up to 4 mm below the weld surface.
2015-04-14
Journal Article
2015-01-0602
Shin-Jang Sung, Jwo Pan, Mohammed Yusuf Ali, Jagadish Sorab, Cagri Sever
Abstract In this paper, the evolution equation for the active yield surface during the unloading/reloading process based on the pressure-sensitive Drucker-Prager yield function and a recently developed anisotropic hardening rule with a non-associated flow rule is first presented. A user material subroutine based on the anisotropic hardening rule and the constitutive relation was written and implemented into the commercial finite element program ABAQUS. A two-dimensional plane strain finite element analysis of a crankshaft section under fillet rolling was conducted. After the release of the roller, the magnitude of the compressive residual hoop stress for the material with consideration of pressure sensitivity typically for cast irons is smaller than that without consideration of pressure sensitivity.
2015-04-14
Technical Paper
2015-01-0598
Xiaona Li, Changqing Du, Yongjun Zhou, Xin Xie, Xu Chen, Yaqian Zheng, Thomas Ankofski, Rodrigue Narainen, Cedric Xia, Thomas Stoughton, Lianxiang Yang
Abstract Accurate determination of the forming limit strain of aluminum sheet metal is an important topic which has not been fully solved by industry. Also, the effects of draw beads (enhanced forming limit behaviors), normally reported on steel sheet metals, on aluminum sheet metal is not fully understood. This paper introduces an experimental study on draw bead effects on aluminum sheet metals by measuring the forming limit strain zero (FLD0) of the sheet metal. Two kinds of aluminum, AL 6016-T4 and AL 5754-0, are used. Virgin material, 40% draw bead material and 60% draw bead material conditions are tested for each kind of aluminum. Marciniak punch tests were performed to create a plane strain condition. A dual camera Digital Image Correlation (DIC) system was used to record and measure the deformation distribution history during the punch test. The on-set necking timing is determined directly from surface shape change. The FLD0 of each test situation is reported in this article.
2015-04-14
Technical Paper
2015-01-1612
Wei Liu, Gangfeng Tan, Jiafan Li, Xin Li, Fuzhao Mou, Yongqiang Ge
Abstract The hydraulic retarder is a significant auxiliary braking device [1] for the heavy duty vehicle. Traditionally, cooling circulatory system of the hydraulic retarder was coupled with the engine cooling system [2], and the thermal energy of the transmission medium would be cooled by the engine radiator ultimately. For this scheme, radiator's spare heat removal capacity could be fully utilized whereas the cooling system is very complicated and is hard to maintain. Furthermore, the corresponding of thermal management system lags behind the power change of the retarder. In this research, integrated cooling evaporation system is developed for the hydraulic retarder, which makes the cooling water contact with the transmission medium through the stator wall, so that it can rapidly response to the thermal variation of the retarder, keep the stability of the oil temperature and meanwhile reduce the risk of cooling medium leakage.
2015-04-14
Journal Article
2015-01-0435
S. Khodaygan, M. Hafezipour
Abstract Kinematic accuracy of the robot end-effector is decreased by many uncertainties. In order to design and manufacture robots with high accuracy, it is essential to know the effects of these uncertainties on the motion of robots. Uncertainty analysis is a useful method which can estimate deviations from desired path in robots caused by uncertainties. This paper presents an applied formulation based on Direct Linearization Method (DLM), for 3D statistical uncertainty analysis of open- loop mechanisms and robots. The maximum normal and parallel components of the position error on the end-effector path are introduced. In this paper, uncertainty effects of both linear and angular variations in performance of spatial open-loop mechanisms and robots are considered.
2015-04-14
Technical Paper
2015-01-0475
Truong Nguyen, John Bell
Abstract Modern automotive electrical and electronic architecture is comprised of the battery and charging system, power distribution boxes, electronic control units, electrical devices, grounds, and the means of connecting all of these together - the wire harness or Electrical Distribution System (EDS). As automotive electrical content and complexity increases, it becomes imperative to optimize the weight, size, cost, and manufacturability of a vehicle [1]. In terms of an EDS, the most potential gain can be realized if the EDS supplier and vehicle Original Equipment Manufacturer (OEM) work together during the advanced electrical & electronic architecture development and packaging design process. Traditionally, the electrical content, harness partitioning, and packaging locations are designed by the vehicle OEM with limited advanced input from the EDS supplier.
2015-04-14
Journal Article
2015-01-0510
Joy Hines Forsmark, Zachary Dowling, Kelsey Gibson, Caroline Mueller, Larry Godlewski, Jacob Zindel, James Boileau
Abstract Magnesium die-cast alloys are known to have a layered microstructure composed of: (1) An outer skin layer characterized by a refined microstructure that is relatively defect-free; and (2) A “core” (interior) layer with a coarser microstructure having a higher concentration of features such as porosity and externally solidified grains (ESGs). Because of the difference in microstructural features, it has been long suggested that removal of the surface layer by machining could result in reduced mechanical properties in tested tensile samples. To examine the influence of the skin layer on the mechanical properties, a series of round tensile bars of varying diameters were die-cast in a specially-designed mold using the AM60 Mg alloy. A select number of the samples were machined to different final diameters. Subsequently, all of the samples (as-cast as well as machined) were tested in tension.
2015-04-14
Technical Paper
2015-01-0506
Toshiyuki Kondo, Shinichiro Watanabe, Nobuhiro Nanba
Abstract Today, conventional requests for automation and modern requests for flexibility in handling product diversity and changes in production volume regarding assembly operation are increasing. In order to satisfy those, the “Innovative Automation Cell” (Refer to Figure 1) has been proposed as an innovative assembly production system in lieu of an assembly line operation, which has been continuing with the use of automatic conveyance. Furthermore, technical developments were implemented, such as “Real-time Position Attitude Correction Technology” and “High-speed Emergency Recovery System”, as well as “Assembly Operation Support System”, to make an easy system for an operator, so as to minimize reduction of run rate in mass production practices. This article addresses the concept of the “Innovative Automation Cell”, the details of the developed technology, the effects of introduction to mass production, and future issues.
2015-04-14
Technical Paper
2015-01-0507
Taro Nakamura
Abstract During the planning of Honda's new plant in Ogawa Japan, which is the new benchmark for developed countries power train plants, there was a project requirement established for a significant reduction in initial investment. In order to improve the competitive edge of module machines, which is the foundation of Honda's existing powertrain machining lines, Honda targeted a reduction in the number of module machines through concurrent machining of multiple workpieces, and minimization of transfer time. By developing exclusive jigs for cylinder heads and blocks, this project was able to meet the original project reduction requirements. In addition, Honda was able to shorten the loading and unloading times of a module machine by developing an exclusive transfer machine specifically for cylinder heads.
2015-04-14
Journal Article
2015-01-0514
Sugrib K. Shaha, Frank Czerwinski, Wojciech Kasprzak, Jacob Friedman, Daolun Chen
Abstract The uniaxial compression test was used to assess the influence of strain amount on the behavior of precipitates and texture of the Al-7%Si-1%Cu-0.5%Mg alloy, modified with micro-additions of V, Zr and Ti. As revealed through metallographic examinations, fracturing and re-orientation of the second-phase particles increased with increasing compression strain. However, the intermetallic particles experienced substantially more frequent cracking than the eutectic silicon. The crystallographic texture was measured and correlated with deformation behavior of the alloy. The weak texture of 11<211> and 111<110> components, detected after casting transformed to a mixture of 1<110>, 112<110> and 111<110> components after room-temperature compression deformation. The intensity of the texture components depended on the strain amount. It is concluded that the texture formation in the studied alloy is controlled by the precipitates formed during solidification of the alloy.
2015-04-14
Journal Article
2015-01-0512
Anthony D. Prescenzi
Abstract Ablation casting is an emerging technology which combines traditional sand molding techniques with rapid cooling due to the use of a water soluble binder. High cooling rates and control of solidification direction allows for exceptional mechanical properties and complex shapes. Through the use of ablation, six different body node castings have been manufactured for the 2016 NSX aluminum space frame. The high mechanical properties allowed these castings to be integrated into the crash structure for energy absorption. Using the traditional casting alloy A356, target mechanical properties were 190 Mpa Yield Strength, 280 Mpa Tensile Strength and 12% min elongation. The high elongation was achieved due to the refined eutectic microstructure produced by high cooling rates. The eutectic microstructure produced by ablation was found to be Level 5 or 6 on the AFS scale. Light weighting could also be achieved when compared to traditional GDC castings.
2015-04-14
Technical Paper
2015-01-0499
Nagarjun Jawahar, Sangamitra Manoharan, Harish Chandran
Abstract Material energy and cost minimization has been the need of the hour off late. The work aims at designing a micro gripping device which has suitable application in bio medical industry; specifically surgical operation of comminuted fracture using CAE software. Being a combination of an inverter and a clip, the ability of the compliant mechanism to be used as a gripper as well as positioner constitutes its rare versatility. The compliant mechanisms are single-piece structures, having no backlash as in case of rigid-body, jointed mechanisms and comparatively cheaper to manufacture. Designed in MATLAB R2008a using the concept of topological optimization, modeled in AutoCAD Mechanical 2011 and analyzed in ANSYS Workbench 13.0; the mechanism is initially designed with a geometrical advantage of 2. The MATLAB code which is an improvement of the 99 line code written by O.
2015-04-14
Technical Paper
2015-01-0497
Monika Filiposka, Ana M. Djuric, Waguih ElMaraghy
Abstract Gantry robots are mainly employed for applications requiring large workspace, with limited higher manipulability in one direction than the others. The Gantries offer very good mechanical stiffness and constant positioning accuracy, but low dexterity. Common gantries are CNC machines with three translational joints XYZ (3DOF) and usually with an attached wrist (+3DOF). The translational joints are used to move the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace. In this paper a full kinematic model for a 6DOF general CNC (gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software.
2015-04-14
Technical Paper
2015-01-0505
Miguel Angel Reyes Belmonte, Colin D. Copeland, Drummond Hislop, George Hopkins, Adrian Schmieder, Scott Bredda, Sam Akehurst
Abstract Pressure and temperature levels within a modern internal combustion engine cylinder have been pushing to the limits of traditional materials and design. These operative conditions are due to the stringent emission and fuel economy standards that are forcing automotive engineers to develop engines with much higher power densities. Thus, downsized, turbocharged engines are an important technology to meet the future demands on transport efficiency. It is well known that within downsized turbocharged gasoline engines, thermal management becomes a vital issue for durability and combustion stability. In order to contribute to the understanding of engine thermal management, a conjugate heat transfer analysis of a downsized gasoline piston engine has been performed. The intent was to study the design possibilities afforded by the use of the Selective Laser Melting (SLM) additive manufacturing process.
2015-04-14
Technical Paper
2015-01-0318
Sonu Thomas, Krishnan Kutty, Vinuchackravarthy Senthamilarasu
Abstract Dense depth estimation is a critical application in the field of robotics and machine vision where the depth perception is essential. Unlike traditional approaches which use expensive sensors such as LiDAR (Light Detection and Ranging) devices or stereo camera setup, the proposed approach for depth estimation uses a single camera mounted on a rotating platform. This proposed setup is an effective replacement to usage of multiple cameras, which provide around view information required for some operations in the domain of autonomous vehicles and robots. Dense depth estimation of local scene is performed using the proposed setup. This is a novel, however challenging task because baseline distance between camera positions inversely affect common regions between images. The proposed work involves dense two view reconstruction and depth map merging to obtain a reliable large dense depth map.
2015-04-14
Journal Article
2015-01-0708
Catherine M. Amodeo, Jwo Pan
Abstract In this paper, mode I and mode II stress intensity factor solutions for gas metal arc welds in single lap-shear specimens are investigated by the analytical stress intensity factor solutions and by finite element analyses. Finite element analyses were carried out in order to obtain the computational stress intensity factor solutions for both realistic and idealized weld geometries. The computational results indicate that the stress intensity factor solutions for the realistic welds are lower than the analytical solutions for the idealized weld geometry. The computational results can be used for the estimation of fatigue lives in a fatigue crack growth model under mixed mode loading conditions for gas metal arc welds.
2015-04-14
Journal Article
2015-01-0706
Zheng-Ming Su, Pai-Chen Lin, Wei-Jen Lai, Jwo Pan
Abstract In this paper, failure modes of dissimilar laser welds in lap-shear specimens of low carbon steel and high strength low alloy (HSLA) steel sheets are investigated based on experimental observations. Micro-hardness tests across the weld zones of dissimilar laser welds were conducted. The hardness values of the fusion zones and heat affected zones are significantly higher than those of the base metals. The fatigue lives and the corresponding failure modes of laser welds as functions of the load ranges are then examined. Optical micrographs of the laser welds before and after failure under quasi-static and cyclic loading conditions are then examined. The failure modes and fatigue behaviors of the laser welds under different loading conditions are different. Under quasi-static loading conditions, a necking failure occurred in the upper low carbon steel sheet far away from the laser weld.
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