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Automotive Plastics Principles of Materials & Process Selection

2019-06-10
Plastic - any class of synthetically-produced organic compounds capable of being molded and hardened into a specific shape or form. This course is designed to offer a basic understanding of plastics and plastic processing. Using plastics can be simple, but there is much more behind producing high performance plastic parts. This seminar will walk you through the molding process, provide a comprehensive look at the variables in the manufacturing mix, and review characteristics of typical automotive plastics such as PP, PVC, ABS, and more.
Technical Paper

Multiphysics Multi-Objective Optimization for Electric Motor NVH

2019-06-05
2019-01-1461
Prediction of noise/vibration at the design stage is important for motor design. However, due to the multiphysics nature of the noise, vibration, harshness (NVH) simulation, an integrated workflow is required for wide adoption across industries [1-5]. ANSYS Workbench provides a platform where electromagnetic, structural and acoustic solvers can communicate with each other without user interventions. Based on the platform, multiple design points can be created with statistical sampling on given design spaces and solved by distributed high performance computers. Response surfaces can then be created with the solution from the design points and used for multi-objective optimization. To demonstrate the optimization workflow, multiple parameters for a motor design similar to the Prius motor are created.
Technical Paper

Numerical Simulation for the Hybrid Process of Sheet Metal Forming and Injection Molding Using Smoothed Particle Hydrodynamics Method

2019-04-02
2019-01-0713
An innovative process to produce polymer-sheet metal components in one single operation is analyzed in this paper. Polymer Injection Forming (PIF) is a hybrid process which combines best in class manufacturing processes viz. sheet metal forming and injection molding process. Consequently, this unique process is characterized by a substantial reduction in capital costs and production time and planning effort while also eliminating the need for maintaining tight manufacturing tolerances. To make use of these capabilities in high-speed injection molding process, understanding the dynamic characteristic of the melt flow is required, which cannot be achieved with regular mesh-base Finite Element (FE) methods due to their need for high computational effort and mesh distortion issue.
Technical Paper

A Systems Approach in Developing a Ultralightweight Outside Mounted Rearview Mirror Using Discontinuous Fiber Reinforced Thermoplastics

2019-04-02
2019-01-1124
Fuel efficiency improvement of automobiles has been a topic of great interest in the past years, especially with the introduction of new CAFE standards. Although there are multiple ways of improving the fuel efficiency of an automobile, light weighting is one of the most common approaches taken by many automotive manufacturers. Importance of lightweighting is more significant in electric vehicles as it directly effects the range. The use of composite materials in place of metals has proven to achieve substantial weight reductions in the past. The focus of using these composite materials for weight reduction was generally limited to major structural components such as BiW and closures, due to the high material cost. Secondary structural components which contribute approximately 30% of the vehicle weight are usually neglected by these weight reduction studies.
Technical Paper

Research on the different behavior of edge cracking limit by adopting the laser cutting method

2019-04-02
2019-01-1264
The edge fracture occurs more frequently during the forming procedure by using the material with higher strength. To avoid the edge fracture that happens during the manufacturing, the edge cracking limit at different pre-strain level needs to be determined. The edge of the part under forming is conventionally manufactured by mechanical cutting, and the edge cracking limit under this circumstance is already heavily studied. In recent years, laser cutting is more applied in the automotive industry to cutting the edge due to the following advantages over mechanical cutting: easier work holding, higher precision, no wearing, smaller heat-affected zone, etc. The change cutting method could lead to a different behavior to the edge cracking limit at different pre-strain level. In this paper, the edge cracking limits of sets of pre-strained coupons with different pre-strain levels are tested. Half of them is cut by the conventional punch method, and the other half uses laser cutting.
Technical Paper

Predicting FLCs of Hot Stamping Boron Steel by Z’-DFC

2019-04-02
2019-01-1089
In this study, combined with an improved Zener-Hollomon parameter (Z’), a previously proposed ductile failure criterion (DFC) is used to predict forming limit curves (FLCs) of Boron steel at hot stamping temperatures. The ductile failure criterion takes into account the critical damage at localized necking or fracture as a function of strain path and initial sheet thickness. The improved Zener-Hollomon equation accounts for the strain rate sensitivity of the material at high temperatures. Compared with published experimental result, the criterion is able to provide accurate prediction of FLCs of different thick Boron sheet steel at different hot stamping temperatures.
Technical Paper

Estimation of Cutting Parameters in Two-Stage Piercing to Reduce Edge Strain Hardening

2019-04-02
2019-01-1092
Edge cracking is a common problem when forming advanced high strength steels (AHSS). A particular case of this issue is during collar forming (or hole extrusion) process, which is widely used in the stamping industry. This study attempts to relate the edge stretchability in collar forming to strain hardening along the pierced edge, as suggested by the Institute of Metal Forming (UTG) of the Technical University of Munich (TUM). The study intends to illustrate how Finite Element simulations can be used to reduce the number of experiments required to improve cutting settings for a given material and thickness. Using CP800 of 4.0 mm thickness, a single-stage piercing operation is compared with a two-stage cutting operation (shaving) in terms of strains (consequently strain hardening) along the pierced edge, calculated by finite element simulation. Results indicated that strains were reduced along the pierced edge by shaving.
Technical Paper

Thoracic Spine Extension Injuries in Occupants with Pre-Existing Conditions during Rear End Collisions

2019-04-02
2019-01-1222
Certain ankylosing spondyloarthropathies such as ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH) can significantly alter clinicopathologic spine biomechanics and injury mechanisms in rear end motor vehicle collisions. AS is an inflammatory disease which can lead to structural impairments of the spine secondary to flowing ossification along the spinal column, including ossification across the spinal discs, facet joints, and ligaments, and has been associated with diffuse osteoporosis of the spine. DISH is characterized by excess bone formation along the spinal column, encompassing the annulus and forming the thickest and strongest bridging of the vertebral bodies at the level of the disc space. In both conditions the spine is generally stiffer and more kyphotic than a healthy spine.
Technical Paper

Bendability Study of 7xxx Aluminum Alloy based on the DIC Technique

2019-04-02
2019-01-1265
Bendability is a critical characteristics of sheet metal during the stamping process in automobile industry. Bending operation plays an important role in the panels forming of vehicles. In this study, the recently developed “incremental bending” method was utilized to evaluate the ambient bendability of 7xxx series avoiding bending crack. A 3D digital image correlation (DIC) measurement system is improved to capture the displacement and strain information on the stretched side of the sheet samples. The background, experimental method and data post-procedure are introduced in detail. After several sequential images acquisition and data processing, the major strain histories on the stretch zone of the samples are measured. With different bending process and parameters, the location of peak strain and the surface major strain distribution were evaluated as a function of R/T ratio (the inner radius over sheet thickness).
Technical Paper

Experimental Study of Springback (Side-Wall-Curl) of Sheet Metal based on SBDS System

2019-04-02
2019-01-1088
Springback is a common phenomenon in automotive manufacturing processes, caused by the elastic recovery of the internal stresses during unloading. A thorough understanding of springback is essential for the design of tools used in sheet metal forming operations. A Stretch-Bend-Draw-System (SBDS) has been used to simulate forming process for two different sheet metals: aluminum and steel. Two levels of pulling force and two die radii have been enforced to the experimental process to get different springback. Also, the Digital Image Correlation (DIC) system has been adopted to capture the sheet contour and measure the amount of side-wall-curl (sheet springback) after deformation. This paper presents the influence of the material properties, force, and die radius on the deformation and springback. A thorough understanding of this phenomenon is essential, seeing that any curvature in the part wall can affect quality and sustainability.
Technical Paper

Effects of Nitrided and Chrome Plated Die Surface Roughness on Friction in Bending Under Tension

2019-04-02
2019-01-1093
Different die surface polish conditions result in a noticeable effect on material flow in stamping, which can lead to splitting, wrinkling, or other surface stretching issues associated with different friction conditions. These occurrences are not only limited to the non-coated dies, but also nitrided and chrome plated dies. To ensure quality control of the stamped parts, the die conditions corresponding to different polishing procedures need to be developed based on measurable parameters such as surface roughness (Ra). The intent of this study is to investigate the effects of nitrided and chrome plated die surface roughness on friction. The Bending-Under-Tension (BUT) test was conducted to simulate the stamping process due to the test’s versatility and flexibility in changing test parameters. The test involves moving sheet metal across a 3/8-inch diameter pin, which substitutes for a die surface. The pin can be modified by material, heat treatment, coating, and surface roughness.
Technical Paper

Numerical modelling of metal forming by SPH with multi-GPU acceleration

2019-04-02
2019-01-1085
Large material distortion, plastic deformation and forging make the numerical modelling of metal forming a difficult task. Grid-based methods such as the Finite Element Method (FEM) are incapable of simulating this process as these schemes suffer from mesh distortion, mesh entanglement and require mesh refinement. The mesh-based numerical frameworks with discontinuous enrichment can model finite deformation problems with limited success. Moreover, the presence of flaws, multiple crack surfaces and their interaction make the simulation even more numerically and computationally intensive. In this regard, the particle-based or meshfree methods are more relevant. There exist several mesh-free methods and among these Smoothed Particle Hydrodynamics (SPH) is a truly meshfree. In SPH the computational domain is discretised by a set of particles. A given particle interacts only with its neighbouring particles through a kernel function with a constant radius.
Technical Paper

Experimental Drawbeads Design Research

2019-04-02
2019-01-1087
In order to constrain the restraining force and control the speed of metal flow, drawbeads are widely used in industry. They prevent wrinkling or necking in formed panels, reduce the binder force, and minimize the usage of sheet metal to make a part. Different drawbead configurations can satisfy various stamping production. Besides local design of drawbeads, other factors like pulling directions, binder angles and single or multiple beads play an important role too. Moreover, it was found that the same beads configuration can own a different rate of change of pulling force on different gaps by experience. In this paper, to study the effect of each factor, the Aluminum and Steel sheet metals were tested to obtain the pulling force as they passed through a draw bead. Three gap cases between a male and a female beads are set to figure out the trend of pulling force.
Technical Paper

Now You See It, Now You Don't - The Magic of Dry Ice in Automotive Plastics

2019-04-02
2019-01-1277
No matter how large or small of an operation, there is a great demand for automotive component manufacturers, increase the productivity of their equipment, improve the quality of their parts, all the while lowering costs. This can be a balancing act between using the most effective technology while working within a shrinking budget. This presentation discusses the advantages of dry ice cleaning solutions in a variety of automotive applications: 1) as a replacement for solvent and/or mechanical cleaning for the removal of contaminants from tooling, at operating temperature and while it is still in the production machine, 2) deflashing plastic molded parts, 3) removing excess film from IMD parts, and 4) the surface preparation of molded plastic parts prior to painting or coating, replacing traditional aqueous washing methods and subsequent drying.
Technical Paper

New High-Pressure Hydroforming Tool Design Reduces Spring Back in Ultra-High Strength Steels

2019-04-02
2019-01-1084
Flexform™ is a high-pressure hydroforming technique using a flexible rubber diaphragm between the liquid pressure medium and sheet metal. No seal is needed between the metal sheet and the pressure medium. Only a lower tool half is required, as the diaphragm will act as a flexible upper tool half. Further, the flexible diaphragm allows for several tools to be used in one and the same forming operation. All kinds of sheet metal and thicknesses may be formed using the technique. Perforated sheets, pre-coated sheets, or sheets with sensitive surfaces in addition to traditional materials. The Flexform technique works well with difficult-to-form sheet materials such as ultra-high strength steel, titanium, and aluminum. However, as with any other cold forming method, spring-back is obtained after forming. High-pressure forming often leads to less spring-back than conventional stamping. Material spring-back is still a factor to take into consideration and needs to be controlled in some way.
Technical Paper

Automotive Gigabit Ethernet Press-Fit Header Design and Performance

2019-04-02
2019-01-0475
As the demand for Gigabit Automotive Ethernet based on single unshielded twisted pair continues to increase, there is a need to expand the market to include robust automotive grade solderless technology. The new Automotive Ethernet solution features Automotive press fit contacts that can both handle the harsh environments of the application and be applied to the PCB without the need for a soldering process. The solution at hand performs up to 1Gbps speeds without the need for current product plastic header housing redesign, which makes the solution compatible with its through-hole counterpart. Other advantages of a solderless solution include the increase in the amount of materials that can suit the application once the temperature requirements of the system decrease.
Technical Paper

A Development of the Holographic Lighting

2019-04-02
2019-01-0846
Automotive lighting perform a function to inform the position and behavior of the vehicle. It also represents a specific design identity of the vehicle or brand identity. Recently it implements the unique three-dimensional effect while using LED. However, a number of LEDs and complex form of the lens shape have to be applied, resulting in the size, weight and cost increase. In this study, holographic technology is applied as another method to realize 3D effect. The hologram uses the coherence of light and records the interference fringe generated by the object beam reflected by the object and the reference beam on the hologram film. At the time of reconstructing, the film is irradiated with only the reference beam to realize a three-dimensional image. The optical system using a hologram was consists of hologram film, a light source and optical components (reflection surfaces) for irradiating the reference beam at an angle to the film.
Technical Paper

Effects of hot molding pressure on physical and mechanical properties of brake friction materials

2019-03-25
2019-01-1443
Hot molding is one of the most important manufacturing processes of friction materials in automotive brake system because it has direct impact on physical and mechanical properties. Porosity and compressibility are significant properties for brake vibration which affect brake noise propensity during sliding. Therefore, the purpose of this work is to study the effects of hot molding conditions on porosity, compressibility, and vibration of friction materials. Molding pressure which is a crucial parameter was varied in the hot molding process. Density, Porosity, hardness, compressibility and frequency response were investigated and analyzed in relation to the manufacturing parameters. Furthermore, the correlation among porosity, compressibility and frequency response were performed in this research. Finally, the optimal hot molding conditions for improving the noise and vibration of friction materials will be analyzed by using statistical technique.
Technical Paper

Improved Briles Rivet Forming Using High-Speed Force Feedback and Improved Die Geometry

2019-03-19
2019-01-1377
Electroimpact and Kawasaki Heavy Industries (KHI) have produced a new riveting process for the forming of Briles type rivets in Boeing 777 and 777X fuselage assemblies. The Briles rivet is typically used for fuselage assembly and is unique in that it has a self-sealing head. Unlike conventional headed rivets such as the NAS1079, this fastener does not require aircraft sealant under the head to be fluid tight. This unique fastener makes for a difficult fastening process due to the fact that interference must be maintained between the hole and fastener shank, as well as along the sides of the fastener head. Common issues with the formed fasteners include gapping under the fastener head and along the shank of the fastener. Electroimpact has employed a host of different technologies to combat these issues with Briles fastening. First, Electroimpact’s patented “Air Gap” system allows the machine to confirm that the head of the rivet is fully seated in the countersink prior to forming.
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