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Viewing 91 to 120 of 20382
2016-04-05
Technical Paper
2016-01-0333
Pavel Lykov, Rustam Baytimerov, Sergey Vaulin, Evgeny Safonov, Dmitry Zherebtsov
Abstract Due to its unique physical properties (high thermal and electric conductivity) copper is one of the most interesting materials in point of view of additive manufacturing in particular of Selective Laser Melting (SLM). But because of the low laser radiation absorption, low melting point and high thermal conductivity it is difficult to fabricate of copper components without pores. Results of many research have been shown that for successful Selective Laser Melting of copper powder is needed high laser power (more than 300 W) and high laser scanning speed (more than 600 mm/s). However now most SLM machines are equipped with laser plants with output power up to 200 W.In this research, SLM machine with 200 W maximum power CO2 laser has been used. For determination of the influence of SLM process parameters on quality of copper parts cubic specimens have been fabricated. The point distance, exposure time and base plate preheating temperature have been changing.
2016-04-05
Journal Article
2016-01-0336
R.J. Urbanic, R. Hedrick, Ana M. Djuric
Abstract When performing trajectory planning for robotic applications, there are many aspects to consider, such as the reach conditions, joint and end-effector velocities, accelerations and jerk conditions, etc. The reach conditions are dependent on the end-effector orientations and the robot kinematic structure. The reach condition feasibility is the first consideration to be addressed prior to optimizing a solution. The ‘functional’ work space or work window represents a region of feasible reach conditions, and is a sub-set of the work envelope. It is not intuitive to define. Consequently, 2D solution approaches are proposed. The 3D travel paths are decomposed to a 2D representation via radial projections. Forward kinematic representations are employed to define a 2D boundary curve for each desired end effector orientation.
2016-04-05
Technical Paper
2016-01-0335
Samuel M. Odeyinka, Ana M. Djuric
Abstract Inverse kinematic solutions of six degree of freedom (DOF) robot manipulation is a challenging task due to complex kinematic structure and application conditions which affects and depend on the robot’s tool frame position, orientation and different possible configurations. The robot trajectory represents a series of connected points in three dimensional space. Each point is defined with its position and orientation related to the robot’s base frames or users teach pendant. The robot will move from point to point using the desired motion type (linear, arc, or joint). This motion requires inverse kinematic solution. This paper presents a detailed inverse kinematic solution for Fanuc 6R (Rotational) robot family using a geometrical method. Each joint angular position will be geometrically analyzed and all possible solutions will be included in the decision equations. The solution will be developed in a parametric manner to cover the complete Fanuc six DOF family.
2016-04-05
Technical Paper
2016-01-0353
Suleman Ahmad, Dimitry Sediako, Anthony Lombardi, C. (Ravi) Ravindran, Robert Mackay, Ahmed Nabawy
Abstract Aluminum alloys have been replacing ferrous alloys in automotive applications to reduce the weight of vehicles. The engine block is a striking example of weight reduction, and is made of Al-Si-Cu-Mg (319 type) alloys. The wear resistance in the engine block is enabled by cast iron liners, and these liners introduce tensile residual stress due to a thermo-mechanical mismatch. Typically, an artificial aging treatment effectively reduces residual stress. In this study, neutron diffraction was used to measure the residual stress profiles along the cylinder bridge of a T5 treated 319 aluminum alloy engine block. Results indicated high tensile residual stresses (200-300 MPa) in the hoop and axial orientation at depths of 50-60 mm below the head deck. The high residual stresses were likely due to a combination of minimal stress relief during artificial aging and stress development during post process cooling.
2016-04-05
Journal Article
2016-01-0344
Mohamed El-Sayed
Abstract Success in lean product realization depends on the ability to specify value from the voice of the customer at the beginning of the process. Value streaming, is therefore essential for assuring that the specified value is being pursued and achieved throughout the process. During lean implementation, however, it is usually assumed that nothing but value will be streamed if wastes are eliminated using value stream mapping. While waste elimination is necessary to make the process leaner and facilitate value streaming it is not sufficient for assuring that specified value is being streamed without structured and formalized participation of customers. With current structure of product realization processes, the voice of the customer is provided during the planning phase at the beginning of the process and customer satisfaction feedback is provided after product launch.
2016-04-05
Technical Paper
2016-01-0342
Rushil Batra, Sahil Nanda, Shubham Singhal, Ranganath Singari
Abstract This research is an attempt to investigate the significance of Value Stream Mapping (VSM) in the lean transformation of manufacturing units (largely automotive) and then apply the same in a tool room. It is an essential tool used to interpret both material and information flow in a system. The tool room under study specializes in production of a large variety of high precision tools for the automotive industry. A product family is chosen to map and analyze various stages of its production process, starting from the raw material (R/M) to the finished goods’ (F/G) stage. VSM is then implemented in the tool room to correctly identify wastes and thus improvement areas to bridge gaps between current and future states. Both current and future state maps are drafted along with usage of other lean tools to justify its implementation in a small setup like tool room.
2016-04-05
Technical Paper
2016-01-0348
Nan Wang, Sergey Golovashchenko
Abstract Stamping die design recommendations attempt to limit the production of burrs through accurate alignment of the upper and lower trimming edges. For aluminum automotive exterior panels, this translates to a clearance less than 0.1 mm. However, quality of sheared edge and its stretchability are affected by stiffness of the cutting tool against opening of the clearance between the shearing edges. The objective of the study is to investigate the influence of stiffness of trimming or piercing dies against opening of the cutting clearance on sheared edge stretchability of aluminum blanks 6111-T4. For experimental study, one side of the sample had sheared surface obtained by the trimming process while the other side of the sample had a smooth surface achieved by metal finish. Burr heights of the sheared edge after different trimming configurations with 10% clearance were measured.
2016-04-05
Technical Paper
2016-01-0346
Patrick Garcia, Jiri Radous, Artur Krol, Jacek Bosek, Caroline Baeten
During the 4 last years, Lean has been successfully implemented in one of the Tenneco’s Business Units: Ride Performance. This paper reflects on the results and more specifically on the third principle of Lean [1] “How to make flow” and on the fifth principle “To strive for perfection” obtained in the fields of “Product Development” related to Processes, Tools and People. Processes and Hard Tools. How to improve the flow in the engineering processes? It will be shown that In general standardized processes supported by some integrated tools and, more specifically Some workload leveling in testing, CAD Departments, Standardization in design processes, testing procedures and prototypes development processes and Standardization and availability of components and parts for prototype building are key enablers to enhance flow in the Product Development.
2016-04-05
Journal Article
2016-01-0317
Yuanzhan Wang, Jason B. Siegel, Anna G. Stefanopoulou
Abstract This paper addresses scheduling of quantized power levels (including part load operation and startup/shutdown periods) for a propane powered solid oxide fuel cell (SOFC) hybridized with a lithium-ion battery for a tracked mobile robot. The military requires silent operation and long duration missions, which cannot be met by batteries alone due to low energy density or with combustion engines due to noise. To meet this need we consider an SOFC operated at a few discrete power levels where maximum system efficiency can be achieved. The fuel efficiency decreases during transients and resulting thermal gradients lead to stress and degradation of the stack; therefore switching power levels should be minimized. Excess generated energy is used to charge the battery, but when it’s fully charged the SOFC should be turned off to conserve fuel.
2016-04-05
Technical Paper
2016-01-0325
Farhan Javed, Salman Javed
Abstract Additive manufacturing has experienced rapid growth over a span of 25 years. Additive manufacturing involves the development of a three-dimensional (3D) object by stacking layer upon layer. Conventional machining techniques involve the removal of material. However, this technique differentiates itself from other techniques by means of addition of the material. The integration of CAD with additive manufacturing has offered the ability to create complex structures. Despite its clear benefits, additive manufacturing suffers from a high initial investment. An average cost of an entry level commercial 3D printer is 600$. A low-cost 3D printer has been designed and built for experimental investigation within a budget of 300$. The paramount process of 3D printing involves a combination of interpreting data from CAD files and controlling the motors using this data. The various design considerations while developing the 3D printer have been discussed.
2016-04-05
Technical Paper
2016-01-0328
Scott Curran, Paul Chambon, Randall Lind, Lonnie Love, Robert Wagner, Steven Whitted, David Smith, Brian Post, Ronald Graves, Craig Blue, Johney Green, Martin Keller
Abstract Rapid vehicle powertrain development has become a technological breakthrough for the design and implementation of vehicles that meet and exceed the fuel efficiency, cost, and performance targets expected by today’s consumer. Recently, advances in large scale additive manufacturing have provided the means to bridge hardware-in-the-loop with preproduction mule chassis testing. This paper details a case study from Oak Ridge National Laboratory bridging the powertrain-in-the-loop development process with vehicle systems implementation using big area additive manufacturing (BAAM). For this case study, the use of a component-in-the-loop laboratory with math-based models is detailed for the design of a battery electric powertrain to be implemented in a printed prototype mule. The ability for BAAM to accelerate the mule development process via the concept of computer-aided design to part is explored.
2016-04-05
Journal Article
2016-01-0371
Wenkai Li, Carlos Engler-Pinto, Haitao Cui, Weidong Wen, Xuming Su
Abstract In this paper, fatigue tests on a cast aluminum alloy (AS7GU-T64) were performed under different frequencies and humidity levels. Tests conducted under conventional frequency in laboratory air have been compared to tests conducted under ultrasonic frequency in dry air, saturated humidity and in distilled water. It was observed that the highest and lowest fatigue lives correspond to ultrasonic fatigue tests in dry air and in distilled water, respectively. Unlike specimens tested at conventional frequency, all of the specimens tested at ultrasonic frequency presented a large amount of slip facets on the fatigue crack propagation fracture surface.
2016-04-05
Technical Paper
2016-01-0370
Zhigang Wei, Yunfei Qu, Dongying Jiang, Limin Luo, Jason Hamilton, Kay Ellinghaus, Markus Pieszkalla
Fatigue life assessment is an integral part of the durability and reliability evaluation process of vehicle exhaust components and systems. The probabilistic life assessment approaches, including analytical, experimental, and simulation, CAE implementation in particular, are attracting significant attentions in recent years. In this paper, the state-of-the-art probabilistic life assessment methods for vehicle exhausts under combined thermal and mechanical loadings are reviewed and investigated. The loading cases as experienced by the vehicle exhausts are first categorized into isothermal fatigue, anisothermal fatigue, and high-temperature thermomechanical fatigue (TMF) based on the failure mechanisms. Subsequently, the probabilistic life assessment procedures for each category are delineated, with emphasis on product validation.
2016-04-05
Technical Paper
2016-01-0364
Guobiao Yang, Tian Bai, Wan Xu, Junrui Li, Lianxiang Yang, Dajun Zhou, Changqing Du
Abstract Dimensional problems for punched holes on a sheet metal stamping part include being undersized and oversized. Some important relationships among tools and products, such as the effect of conical punch tip angle, are not fully understood. To study this effect, sheets of AA6016 aluminum and BH210 steel were punched by punches with different conical tip angles. The test method and test results are presented. The piercing force and withdrawing force when using conical punches were also studied. The results indicate that the oversize issue for a punched hole in a stamped panel is largely due to the combination of the conical tip effect and the stretching-release effect.
2016-04-05
Journal Article
2016-01-0374
Zhigang Wei, George Zhu, Litang Gao, Limin Luo
Vehicle exhaust components and systems under fatigue loading often show multiple failure modes, which should be treated, at least theoretically, with rigorous advanced bi-modal and multi-modal statistical theories and approaches. These advanced methods are usually applied to mission-critical engineering applications such as nuclear and aerospace, in which large amounts of test data are often available. In the automotive industry, however, the sample size adopted in the product validation is usually small, thus the bi-modal and multi-modal phenomena cannot be distinguished with certainty.
2016-04-05
Technical Paper
2016-01-0358
Saeid Nasheralahkami, Sergey Golovashchenko, Kaicen Pan, Lindsay Brown, Bindiya Gugnani
Abstract In recent years, implementation of dual phase (DP) Advanced High Strength Steels (AHSS) and Ultra High Strength Steels (UHSS) is increasing in automotive components due to their superior structural performance and vehicle weight reduction capabilities. However, these materials are often sensitive to trimmed edge cracking if stretching along sheared edge occurs in such processes as stretch flanging. Tool wear is another major issue in the trimming of UHSS because of higher contact pressures at the interface between cutting tools and sheet metal blank caused by UHSS’s higher flow stresses and the presence of a hard martensitic in the microstructure. The objective of the present paper is to study the influence of trimming conditions and tool wear on quality of trimmed edge of DP980 steel sheet. For this purpose, mechanically trimmed edges were characterized for DP980 steel, sheared with six different cutting clearances (from 4% to 40% of the sheet thickness).
2016-04-05
Journal Article
2016-01-0356
Hua-Chu Shih
Prephosphated steels have been developed by applying the phosphate coating on zinc coated sheet steels to increase the lubricity in the automotive stamping process and adding extra corrosion protection. The prephosphate coating was also found to be able to further absorb the lubricant, which can reduce the oil migration and excessive amount of lubricant dripping on the die surface and the press floor. Due to its enhanced lubricity characteristic, the applications have been expanded to more-recently developed advanced high strength steels (AHSS). Because of the higher strength of AHSS, it is crucial to understand their performance under more extreme forming conditions such as higher die temperature, contact pressure and sliding speed, etc. The intent of this study is to investigate the tribological performance and die wear behavior of prephosphated AHSS in the die tryout and production conditions.
2016-04-05
Technical Paper
2016-01-0355
Takashi Iwama
Abstract Although reduction of the thickness of materials used in the automobile body is important for weight reduction, reducing the thickness of outer panels deteriorates dent resistance and surface distortion. To investigate the potential for weight reduction, the factors which influence the surface distortion and dent resistance properties were evaluated quantitatively with the aim of securing these properties. The materials used in these experiments were a tensile strength (TS) 340MPa grade bake hardenable (BH) steel sheet, which is often used in door outers, and a TS 440MPa grade BH steel sheet for outer panels. Surface distortion increases as a result of higher yield point (YP). It is possible to suppress the increase in surface distortion by increasing the blank holding force (BHF) in press forming. However, because this reduces the BHF range to the forming limit, application of low YP material is considered to be more advantageous for suppressing surface distortion.
2016-04-05
Journal Article
2016-01-0363
HaiYan Yu, ZeZhen He, JiaYi Shen
Abstract The work-hardening response of TRIP780 steel subjected to strain-path changes was investigated using two-stage tension experiments. Large specimens were prestrained and then sub-sized samples were subjected to tension along various directions. The influence of strain-path changes on flow stress and work hardening performance was discussed in detail. The specific plastic work was calculated to compare the kinematic hardening behaviour after strain-path changes. The results showed that transient hardening was observed for TRIP780 sheets subjected to orthogonal strain-path change. The strain-hardening exponent (n-value) was influenced by prestraining levels and the strain path. The n-value exhibited a greater decrease under an orthogonal strain-path change. Prestraining can delay the onset of high work hardenability of TRIP steels. It is meaningful for the safety design of vehicles.
2016-04-05
Journal Article
2016-01-0360
Cédric Georges, Xavier Vanden Eynde, Frank Goodwin
Advanced high strength steels used in automotive body and structure applications are exposed to hydrogen during several steps of their processing. For galvanized sheet steel, one of these is the continuous galvanizing process, during which the sheet is prepared for coating in a H2-N2 furnace. This paper shows the relationship between hydrogen uptake in DP600 and DP980 grades, together with an IF steel control composition, and galvanizing process conditions. Hydrogen uptake is strongly dependent on the furnace atmosphere and the amount of martensite in the steel but has little dependence on the soaking time, the humidity of the furnace atmosphere, or the temperature within the usual intercritical annealing range. Rapid outgassing was observed during overageing prior to the zinc dipping. Slow strain rate tests showed that there was no loss of ductility in galvanized samples that had been treated in a 5% H2 atmosphere or that had been overaged before the galvanizing.
2016-04-05
Journal Article
2016-01-0359
Jeff Wang, Charles Enloe, Jatinder Singh, Curt Horvath
Abstract Impact toughness (or resistance to fracture) is a key material property for press hardened steel used in construction of the safety-critical elements of automotive body structures. Prior austenite grain size, as primarily controlled by the incoming microstructure and austenitization process, is a key microstructural feature that influences the impact toughness of press hardened steel. In this paper, a special Charpy V-notch impact test is developed to quantify the impact toughness of press hardened steel sheets with various prior austenite grain sizes, by stacking a number of thin sheets via mechanical riveting. Both the ductile-to-brittle transition temperature and upper shelf energy are analyzed in an effort to establish a correlation between impact toughness and prior austenite grain size. Within tested conditions, impact performance shows only a slight decrease as the prior austenitic grain size increases from 18 to 38 microns.
2016-04-05
Journal Article
2016-01-0542
Hiroshi Kawaguchi, Osamu Funatsumaru, Hiroyoshi Sugawara, Hiroshi Sumiya, Takanobu Iwade, Tomitaka Yamamoto, Takashi Koike, Ryuta Kashio
Abstract Trivalent chromium passivation is used after zinc plating for enhancing corrosion resistance of parts. In the passivating process, the amount of dissolved metal ions (for example zinc and iron) in the passivation solution increases the longer the solution is used. This results in a reduced corrosion resistance at elevated temperatures. Adding a top coat after this process improves the corrosion resistance but has an increased cost. To combat this, we strove to clarify the mechanism of decreased corrosion resistance and to develop a trivalent chromium passivation with a higher corrosion resistance at elevated temperatures. At first, we found that in parts produced from an older solution, the passivation layer has cracks which are not seen in parts from a fresh/new solution. These cracks grow when heated at temperatures over 120 degrees Celsius.
2016-04-05
Journal Article
2016-01-0543
Takashi Hara, Masaki Kato, Kazuki Mizutani
Abstract There are such outside door handles called smart handles which have a transmitting antenna, a lock/unlock sensor, and a sensor detection circuit, with which operation of door lock is possible just by "touching" the electrostatic-capacitance type sensor of the handles.As the design of the outside handles, body color painting and Cr plating are adopted. However, if plating is applied over the entire surface of a smart handle, electromagnetic waves transmitted from the antenna will be blocked since plating material is electrically conductive. In addition to this, touching a part other than the sensor may change the electrostatic-capacitance of the sensor, which results in unwanted functioning of the lock/unlock sensor. Because of this, only part of the handle, which does not hinder the transmission of electromagnetic waves and does not cause unwanted functioning, is covered by plating, that is called, "Partially plated specifications" (Figure 1).
2016-04-05
Journal Article
2016-01-0504
Shin-Jang Sung, Jwo Pan
Abstract Analytical stress intensity factor solutions for welds in lap-shear specimens of equal thickness under pinned and clamped loading conditions based on the beam bending theory are presented and examined. Finite element analyses are also employed to obtain the stress intensity factor solutions for welds in lap-shear specimens under both clamped and pinned loading conditions. The computational solutions are compared well with the analytical solutions. The results of the analytical and computational solutions indicate that the bending moments at the clamped edges reduce the mode I and II stress intensity factor solutions by about 7% to 10% for the given specimen geometry. The effects of the clamped grips depend on the ratio of the weld width to the specimen length. Comparisons of the stress intensity factor solutions suggest that the fatigue lives of the welds in lap-shear specimens under clamped loading conditions should be higher than those under pinned loading conditions.
2016-04-05
Journal Article
2016-01-0505
Pai-Chen Lin, Shihming Lo
Abstract A concept of combining friction stir spot welding (FSSW) and clinching, denoted as friction stir clinching (FSC), was proposed to join alclad 2024-T3 aluminum sheets. A tool, having a smooth probe and a flat shoulder, and a die, having a circular cavity and a round groove, were used to make FSC joints. The failure loads and fatigue lives of FSC joints made by various punching depths, rotational speeds, and dwelling times, were evaluated to obtain the admissible processing parameters. Optical micrographs of the FSC joints, before and after failure, were examined to understand the effects of processing parameters on the mechanical interlock and alclad layer distribution, which strongly correlate to the failure load, failure mode, and fatigue life of FSC joints. Finally, the static and fatigue performance of FSC joints made by the admissible processing parameters was obtained. The feasibility of the FSC process for alclad 2024-T3 aluminum sheets was confirmed.
2016-04-05
Technical Paper
2016-01-0503
Evandro Giuseppe Betini, Francisco Carlos Cione, Cristiano Stefano Mucsi, Marco Antonio Colosio, Jesualdo Luiz Rossi, Marcos Tadeu D'Azeredo Orlando
Abstract This paper reports the experimental efforts in recording the 2-dimensional temperature distribution on autogenous thin plates of UNS S32304 steel during welding. The butt-welded autogenous joints were experimentally performed by the GTAW (Gas Tungsten Arc Welding) process with either argon or argon-2%nitrogen atmospheres. The temperatures cycles were recorded by means of thermocouples embedded by spot welding on the plate's surfaces and connected to a multi-channel data acquisition system. The laser flash method (LFM) was also used for the determination thermal diffusivity of the material in the thickness direction. The temperature curves suggest a relationship between the microstructures in the solidified and the heat affected zone with the diffusivity variation. This is a region where there had been a major incidence of heat. The obtained results validate the reliability of the experimental used apparatus.
2016-04-05
Journal Article
2016-01-0506
Daisuke Tomomatsu
Abstract This study developed technology for simultaneously welding heterogeneous resin tubes in order to weld and integrate resin tubes with two different specifications (low temperature and high temperature). The aim of integration was cost and weight reduction. The cost reduction due to reducing the number of parts exceeded the increase in material cost due to a change to resin materials. Base material fracture of the resin tubes was set as the breaking format condition, and the welding parameters of the joint part rotations and the friction time between the joint part and the resin tubes were specified as the weld strength judgment standard. In addition, the fused thickness determined by observing the cross-section after welding was specified as the weld quality judgment standard. The range over which weld boundary peeling does not occur and weld strength is manifest was clarified by controlling the welding parameters and the fused thickness.
2016-04-05
Journal Article
2016-01-0499
Xu Zhang, Jennifer Johrendt
Abstract Successful manufacture of Carbon Fibre Reinforced Polymers (CFRP) by Long-Fibre Reinforced Thermoplastic (LFT) processes requires knowledge of the effect of numerous processing parameters such as temperature set-points, rotational machinery speeds, and matrix melt flow rates on the resulting material properties after the final compression moulding of the charge is complete. The degree to which the mechanical properties of the resulting material depend on these processing parameters is integral to the design of materials by any process, but the case study presented here highlights the manufacture of CFRP by LFT as a specific example. The material processing trials are part of the research performed by the International Composites Research Centre (ICRC) at the Fraunhofer Project Centre (FPC) located at the University of Western Ontario in London, Ontario, Canada.
2016-04-05
Journal Article
2016-01-0501
Seung Hoon Hong, Frank Yan, Shin-Jang Sung, Jwo Pan, Xuming Su, Peter Friedman
Abstract Failure mode and fatigue behavior of flow drill screw (FDS) joints in lap-shear specimens of aluminum 6082-T6 sheets with and without clearance hole are investigated based on experiments and a structural stress fatigue life estimation model. Lap-shear specimens with FDS joints were tested under cyclic loading conditions. Optical micrographs show that the failure modes of the FDS joints in specimens with and without clearance hole are quite similar under cyclic loading conditions. The fatigue lives of the FDS joints in specimens with clearance hole are longer than those of the FDS joints in specimens without clearance hole for the given load ranges under cyclic loading conditions. A structural stress fatigue life estimation model is adopted to estimate the fatigue lives of the FDS joints in lap-shear specimens under high-cycle loading conditions.
2016-04-05
Technical Paper
2016-01-0500
Akira Kato, Masayuki Takano, Kohei Hase, Satoko Inuzuka, Toshiyuki Dobashi, Tsuyoshi Sugimoto, Nobuaki Takazawa
Abstract In this report, adhesion mechanism between epoxy resin and primer and between primer and Ni platting in Hybrid vehicle (HV) was investigated. Adhesion forces are thought to be a combination of mechanical bond forces (such as anchor effect), chemical bond forces and physical bond forces (such as hydrogen bonding and Van der Waals force). Currently there is insufficient understanding of the adhesion mechanism. In particular, the extent to which the three bond forces contribute to adhesion strength. So the adhesion mechanism of polyimide primers was analyzed using a number of different methods, including transmission electron microscope (TEM) and atomic force microscope (AFM) observation, to determine the contributions of the three bonding forces. Molecular simulation was also used to investigate the relationship between adhesion strength and the molecular structure of the primer.
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