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Experimental Study on Static and Fatigue Behavior of a Short Glass Fiber Reinforced Polypropylene

FCA US LLC-Mingchao Guo, Congyue Wang, Jian Tao, Ramchandra Bhandarkar
InDepth Engineering Solutions-Johnson Joseph
  • Technical Paper
  • 2020-01-0190
To be published on 2020-04-14 by SAE International in United States
One approach of reducing vehicle weight is using composite materials. Fiber reinforced polypropylene is one of the most popular composite materials. To improve accuracy in prediction of durability performance of structures made of this kind of composite material, static and fatigue properties of a 30% fiber reinforced polypropylene have been physically studied. This paper describes details of test coupon design, fabrication and test setup of both quasi static and fatigue tests. In this study, various fiber orientation (0, 20, 90 degrees & knit line), temperature (-40, 23 and 80 degree C), mean stress (R=-1.0, -0.5, -0.2, 0.1 and 0.4) have been considered and the result of the tests discussed.
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Fatigue Life Prediction of HVAC Pipe Assembly for Measured Powertrain Load by Virtual Simulation

FCA Engineering India Pvt., Ltd.-Sathish Kumar Pandi, C Elango, Kameswara Rao Appana, Roshan N. Mahadule, DivaKaruni Murali Krishna
  • Technical Paper
  • 2020-01-0188
To be published on 2020-04-14 by SAE International in United States
Structural durability of automotive components is one of the key requirements in design and development of today’s automobiles. Virtual simulations are used to estimate component durability to save the cost and time required to build the components and testing.The objective of this work is to find the service life of automotive HVAC pipe assembly by calculating cumulative fatigue life for operation under actual powertrain load conditions. Modal transient response analysis is performed with the measured powertrain load time history. Strain based fatigue life analysis is carried out using modal superposition method (MSM). The estimated fatigue life was compared with the physical test results. This paper also explains the root cause of low fatigue life on pipe assembly and provide the solution.
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Design of the powder metal shift fork and sleeve

Czech Technical University-Gabriela Achtenova, Jiri Pakosta
  • Technical Paper
  • 2020-01-1322
To be published on 2020-04-14 by SAE International in United States
The paper will present the design of shift fork for automotive manual gearbox dedicated for the manufacturing with help of powder metal technology. Based on limitations and requirements of new production technology of shifting sleeve, a new prototype of shifting sleeve is created, for which are new shifting forks then designed. The form of the prototype of the shift sleeve respected the requirements of the new technology, but from cost reason, it was manufactured from steel. The shift fork was changed accordingly to the new form of the shift sleeve. The functionality of several forks with different tolerances was tested. Prototypes were put through functional and durability tests on testing bench in real automotive gearbox. The test were accomplished on the inertia test stand. Drawings and CAD models of tested prototypes, custom tools and designed shift forks will be described.
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Frame Structure Durability Development Methodology for Various Design Phases

FCA Engineereing India Pvt., Ltd.-Raghavendra Byali, Venkatesh Naik
FCA US LLC-Chandra Thandhayuthapani, Barry Lin, Jianghui Mao
  • Technical Paper
  • 2020-01-0196
To be published on 2020-04-14 by SAE International in United States
It is a challenging task to find an optimal design concept for a truck frame structure given the complexity of loading conditions, vehicle configurations, packaging and other requirements. In addition, there is a great emphasis on light weight frame design to meet stringent emission standards. This paper provides a framework for fast and efficient development of a frame structure through various design phases, keeping durability in perspective while utilizing various weight reduction techniques. In this approach frame weight and stiffness are optimized to meet strength and durability performance requirements.Fast evaluation of different frame configurations during the concept phase (I) was made possible by using DFSS (Design for Six Sigma) based system synthesis techniques. This resulted in a very efficient frame ladder concept selection process. Frame gauge optimization during the subsequent development phase (II) utilizing a newly developed damage based approach greatly reduced the number of design iterations relative to a typical stress based approach. In the light weighting phase (III) that followed, a method was established to effectively locate and optimize lightening holes using fatigue…
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N&V Component Structural Integration and Mounted Component Durability Implications

General Motors LLC-Mark Stebbins, Joseph Schudt
  • Technical Paper
  • 2020-01-1396
To be published on 2020-04-14 by SAE International in United States
Exterior component integration presents competing performance challenges for balanced exterior styling, safety, ‘structural feel’ [1] and durability. Industry standard practices utilize noise and vibration mode maps and source-path-receiver [2] considerations for component mode frequency placement. This modal frequency placement has an influence on ‘structural feel’ and durability performance. Challenges have increased with additional styling content, geometric overhang from attachment points, component size and mass, and sensor modules. Base excitation at component attachment interfaces are increase due to relative positioning of the suspension and propulsion vehicle source inputs. These components might include headlamps, side mirrors, end gates, bumpers and fascia assemblies. Here, we establish basic expectations for the behavior of these systems, and ultimately consolidate existing rationales that are applied to these systems. We consider a simple two degree-of-freedom system subject to a base excitation consisting of masses attached via springs and dampers. Component mode decoupling, vibration amplification and basic design guidance relationships are suggested.
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Analysis of Basic Directions of Accelerated Testing Development

Sohar Inc.-Lev Klyatis
  • Technical Paper
  • 2020-01-0533
To be published on 2020-04-14 by SAE International in United States
This paper provides the author’s analysis of accelerated testing development. It considers four basic directions related to this development, specifically: 1) field accelerated testing; 2) laboratory testing using computer (software) simulation; 3) laboratory or proving ground testing with physical simulation of high stress inputs; 4) accelerated reliability/durability testing (ART/ADT) as a necessary component of a system that leads to successful prediction of product efficiency.
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DFD Stratagem Investigation on Suspension Subframe Durability Test with Spindle Coupled Road Test Simulator

F.tech R&D North America Inc.-Jianghua Gao, Matt Guo, Xin Zhang, Xiao Yu
  • Technical Paper
  • 2020-01-0992
To be published on 2020-04-14 by SAE International in United States
In order to replicate the vehicle chassis proving ground (PG) durability test on the laboratory half vehicle spindle coupled Road Test Simulator (RTS), a drive file which can excite the actuators of the RTS to duplicate the chassis component stress state need to be developed. Traditionally the Drive File Development (DFD) aims to match the spindle forces and moments in addition with some supplement channels such as the tierod axial forces and the spring travels. However the suspension subframe which was connected to the vehicle body may particularly experience a different stress state on the RTS due to the boundary condition discrepancy between the vehicle PG test and the laboratory RTS test. In this paper, the investigation of the different boundary conditions impact on the chassis structures’ stress state is conducted both physically and virtually. It’s proved that the subframe stress state has a non-negligible difference from full vehicle PG test to the half vehicle spindle coupled RTS test using the conventional DFD stratagem. Thus, a special DFD stratagem which employees the subframe strain road…
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Durability study of automotive additive manufactured specimens

Colorado Photopolymer Solutions-Amelia Davenport, Neil Cramer
Eastern Michigan University-Forough Zareanshahraki
  • Technical Paper
  • 2020-01-0957
To be published on 2020-04-14 by SAE International in United States
The long term weathering behavior of three different 3D printable, non-stabilized UV cure resin formulations (A and B with thiol-ene, and C with acrylate chemistry) was studied using tensile testing, nano-indentation, and photoacoustic infrared (PAS-FTIR) spectroscopy. To this end, type IV tensile bars were printed from each resin system using a DLP 3D printer, and were post UV-cured under a broad spectrum source. Systems A and C showed a similar trend after weathering - they first experienced an increase in modulus and tensile strength, likely due to additional crosslinking of the residual unreacted species. This increase in mechanical properties was followed by a drop in modulus, tensile strength, and percent elongation due to the over-crosslinking and consequent embrittlement. Sample B, however, showed remarkable retention of the mechanical properties before/after weathering. Nano-indentation results were in good agreement with the tensile properties, showing a similar trend in hardness variations. Although systems A and C outperformed system B in photooxidation performance, all three systems demonstrated promising results considering no hindered amine light stabilizers (HALS) were used in the…
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Estimation of the Mechanism to Suppress Water Degradation of 1K Heat-Curing Epoxy Adhesive with High Durability

Aisin Chemical Co., Ltd.-Kazumasa Sakaguchi
  • Technical Paper
  • 2020-01-0227
To be published on 2020-04-14 by SAE International in United States
In recent years, structural adhesives have been used to improve the rigidity, shock resistance, etc. of joints, and the requirements for these characteristics are expected to expand further. However, heat, loads, water, etc. can become deterioration factors for adhesives, and the consequent loss of strength is known to occur. In this study, the author has focused on water absorption deterioration, considered as one of the largest deterioration factors for adhesives, and has succeeded in providing high-water resistance to a one-component(1K) heat-curing epoxy adhesive through the addition of appropriate additives. This adhesive exhibited no hydrolysis during the 14-day 70 °C, 100% RH deterioration acceleration test, and strength retention and cohesive failure rates of 100% have been confirmed. In this study, the factors that provide high durability to the adhesive are identified, and the mechanism of how these factors suppress water absorption deterioration has been estimated.
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Full Body Car Analysis in the Time and Frequency Domains - Sheet, Spot and Seam Weld Fatigue Benchmark Studies

CAEfatigue, Ltd.-Neil Bishop, Stuart Kerr
Desktop Engineering Ltd.-Andy Woodward
  • Technical Paper
  • 2020-01-0195
To be published on 2020-04-14 by SAE International in United States
The fatigue analysis of a full car body requires the sheet metal (sheet fatigue), spot welds (spot weld fatigue) and seam welds (seam weld fatigue) to be thoroughly evaluated for durability. Traditionally this has always been done (via separate processes) in the time domain but recently new techniques have been implemented to perform all of these tasks in the frequency domain with numerous advantages. This paper will summarize the frequency domain process and then compare the results (and performance) against the more usual time base result