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Technical Paper

One piece hot formed AB ring reinforcement

2018-09-03
2018-36-0022
The usage of Boron steel in the South American automotive industry has been increasing in recent years. Considering its high hardening properties, sheet metal parts can only be manufactured using a hot forming process, as compared to a conventional cold forming process; however, the hot stamping process offers the advantage to stamp a part in a single die vs. multiple dies using a regular cold stamping process. The main objective is to present the advantages of constructing the whole AB ring reinforcement out of Boron steel and made out of a single die, and no welding among the A pillar reinforcement, B Pillar reinforcement and rocker panel. This type of design has helped to achieve crash safety performance goals, enhance the structural characteristics of joints, improve dimensional control, reduce the number of welds, manage BIW overall weight and improve torsion rigidity.
Technical Paper

Experimental Investigation on the Influence of Pressure Wheel Design on Heat Dissipation for a Laser Robotic End of Arm Tooling

2018-04-03
2018-01-1235
The initiative of this paper is focused on improving the heat dissipation from the pressure wheel of a laser welding assembly in order to achieve a longer period of use. The work examines the effects of different geometrical designs on the thermal performance of pressure wheel assembly during a period of cooling time. Three disc designs were manufactured for testing: Design 1 – a plain wheel, Design 2 – a pierced wheel, and Design 3 – a wheel with ventilating vanes. All of the wheels were made of carbon steel. The transient thermal reaction were compared. The experimental results indicate that the ventilated wheel cools down faster with the convection in the ventilated channels, while the solid plain wheel continues to possess higher temperatures. A comparison among the three different designs indicates that the Design 3 has the best cooling performance.
Technical Paper

Deconstruction of UN38.3 into a Process Flowchart

2017-03-28
2017-01-1208
This paper will discuss a compliance demonstration methodology for UN38.3, an international regulation which includes a series of tests that, when successfully met, ensure that lithium metal and lithium ion batteries can be safely transported. Many battery safety regulations, such as FMVSS and ECE, include post-crash criteria that are clearly defined. UN38.3 is unique in that the severity of the tests drove changes to battery design and function. Another unique aspect of UN38.3 is that the regulatory language can lead to different interpretations on how to run the tests and apply pass/fail criteria; there is enough ambiguity that the tests could be run very differently yet all meet the actual wording of the regulation. A process was created detailing exactly how to run the tests to improve consistency among test engineers. As part of this exercise, several tools were created which assist in generating a test plan that complies with the UN38.3 regulation.
Technical Paper

Robust Observer Roll Rate Sensor Fault Detection

2017-03-28
2017-01-1572
The detection and diagnosis of sensor faults in real-time is necessary for satisfactory performance of vehicle Electronic Stability Control (ESC) and Roll Stability Control (RSC) systems. This paper presents an observer designed to detect faults of a roll rate sensor that is robust to model uncertainties and disturbances. A reference vehicle roll angle estimate, independent of roll-rate sensor measurement, is formed from available ESC inertial sensor measurements. Residuals are generated by comparing the reference roll angle and roll rate, with the observer outputs. Stopping rules based on the current state of the vehicle and the magnitude of the residuals are then used to determine if a sensor fault is present. The system’s low order allows for efficient implementation in real-time on a fixed-point microprocessor. Modification of the roll rate sensor signal during in vehicle experiments shows the algorithm’s ability to detect faults.
Technical Paper

The Application of a One-Way Coupled Aerodynamic and Multi-Body Dynamics Simulation Process to Predict Vehicle Response during a Severe Crosswind Event

2017-03-28
2017-01-1515
Industry trends towards lighter, more aerodynamically efficient road vehicles have the potential to degrade a vehicle’s response to crosswinds. In this paper, a methodology is outlined that indirectly couples a computational fluid dynamics (CFD) simulation of the vehicle’s aerodynamic characteristics with a multi-body dynamics simulation (MBD) to determine yaw, roll and pitch response characteristics during a severe crosswind event. This one-way coupling approach mimics physical test conditions outlined in open loop test procedure ISO 12021:2010 that forms part of the vehicle sign-off criterion at Ford Motor Company. The methodology uses an overset mesh CFD method to drive the vehicle through a prescribed crosswind event, providing unfiltered predictions of vehicle force and moment responses that are used as applied forces in the MBD model. The method does not account for changes in vehicle attitude due to applied aerodynamic forces and moments.
Technical Paper

Wear of D2 Tool Steel Dies during Trimming DP980-type Advanced High Strength Steel (AHSS) for Automotive Parts

2017-03-28
2017-01-1706
Automobile body panels made from advanced high strength steel (AHSS) provide high strength-to-mass ratio and thus AHSS are important for automotive light-weighting strategy. However, in order to increase their use, the significant wear damage that AHSS sheets cause to the trim dies should be reduced. The wear of dies has undesirable consequences including deterioration of trimmed parts' edges. In this research, die wear measurement techniques that consisted of white-light optical interferometry methods supported by large depth-of-field optical microscopy were developed. 1.4 mm-thick DP980-type AHSS sheets were trimmed using dies made from AISI D2 steel. A clearance of 10% of the thickness of the sheets was maintained between the upper and lower dies. The wear of the upper and lower dies was evaluated and material abrasion and chipping were identified as the main damage features at the trim edges.
Technical Paper

An Indirect Tire Health Monitoring System Using On-board Motion Sensors

2017-03-28
2017-01-1626
This paper proposes a method to make diagnostic/prognostic judgment about the health of a tire, in term of its wear, using existing on-board sensor signals. The approach focuses on using an estimate of the effective rolling radius (ERR) for individual tires as one of the main diagnostic/prognostic means and it determines if a tire has significant wear and how long it can be safely driven before tire rotation or tire replacement are required. The ERR is determined from the combination of wheel speed sensor (WSS), Global Positioning sensor (GPS), the other motion sensor signals, together with the radius kinematic model of a rolling tire. The ERR estimation fits the relevant signals to a linear model and utilizes the relationship revealed in the magic formula tire model. The ERR can then be related to multiple sources of uncertainties such as the tire inflation pressure, tire loading changes, and tire wear.
Technical Paper

A Method of Evaluating the Joint Effectiveness on Contribution to Global Stiffness and NVH Performance of Vehicles

2017-03-28
2017-01-0376
While Advanced High Strength Steels (AHSS) and the next generation AHSS grades offer improved crash safety and reduced weight for vehicles, the global stiffness and NVH performance are often compromised due to reduced material thickness. This paper discusses an advanced method of evaluating the joint effectiveness on contribution to global stiffness and NVH performance of vehicles. A stiffness contribution ratio is proposed initiatively in this research, which evaluates the current contribution of the joints to the global stiffness and NVH performance of vehicles. Another parameter, joint effectiveness factor, has been used to study the potential of each joint on enhancing the global stiffness. The critical joints to enhance the vehicle stiffness and NVH performance can be identified based on above two parameters, and design changes be made to those critical joints to improve the vehicle performance.
Technical Paper

Effect of Engine Motion on the Fatigue Life of Cooling Components

2017-03-28
2017-01-0337
Ensuring durability is one of the key requirements while developing cooling modules for various powertrains. Typically, road surface induced loads are the main driving force behind mechanical failures. While developing the components, road load accelerations are utilized in CAE simulations to predict the high-stress regions and estimate the fatigue life of the components mounted on the body. In certain scenarios where components are mounted to the body and attached to the engine with hoses, the components can experience additional loads associated with engine vibration. This attachment scheme requires a different analysis methodology to determine fatigue life. In the proposed paper, we look at the effect of engine motion (EM) on the fatigue life of internal transmission oil cooler (ITOC) which is mounted on the body through radiator and is simultaneously connected to the engine using a steel pipe. We propose a new CAE methodology taking into account the engine motion displacements.
Journal Article

CAE Method for Evaluating Mechanical Performance of Battery Packs under Mechanical Shock Testing

2017-03-28
2017-01-1193
Mechanical shock tests for lithium metal and lithium-ion batteries often require that each cell or battery pack be subjected to multiple shocks in the positive and negative directions, of three mutually perpendicular orientations. This paper focuses on the no-disassembly requirement of those testing conditions and on the CAE methodology specifically developed to perform this assessment. Ford Motor Company developed a CAE analysis method to simulate this type of test and assess the possibility of cell dislodging. This CAE method helps identify and diagnose potential failure modes, thus guiding the Design Team in developing a strategy to meet the required performance under shock test loads. The final CAE-driven design focuses on the structural requirement and optimization, and leads to cost savings without compromising cell or pack mechanical performance.
Journal Article

Damping properties and NVH Modal Analysis Results of Carbon Fiber Composite Vehicle Components

2017-03-28
2017-01-0500
With the continuing challenges of future fuel economy targets carbon fiber composite materials are one facet of a lightweighting strategy to enable reduced fuel consumption. In general, use of lightweight materials such as carbon fiber composites in vehicle design generates vehicle NVH performance degradation. To address this potential issue at the design phase, there is a need to develop correlated CAE models for carbon fiber vehicle parts to evaluate the NVH impact of carbon fiber composite material use in vehicle design. To develop correlated CAE models for lightweight vehicle design with the use of carbon fiber composite vehicle body parts, an experimental study was conducted to determine the material and NVH characteristics of the carbon fiber composite materials. In this paper, the damping properties and NVH modal analysis results for structural carbon fiber thermoset composite panels and body parts (B-pillar upper insert and B-pillar lower insert) is presented.
Technical Paper

Evolution of Engine Air Induction System Hydrocarbon Traps

2017-03-28
2017-01-1014
Engine air induction systems hydrocarbon trap (HC trap) designs to limit evaporative fuel emissions, have evolved over time. This paper discusses a range of HC traps that have evolved in engine air induction systems. (AIS) The early zeolite flow through HC trap utilized an exhaust catalyst technology internal stainless steel furnace brazed substrate coated with zeolite media. This HC trap was installed in the AIS clean air tube. This design was heavy, complicated, and expensive but met the urgency of the implementation of the new evaporative emissions regulation. The latest Ford Motor Company HC trap is a simple plastic tray containing activated carbon with breathable non-woven polyester cover. This design has been made common across multiple vehicle lines with planned production annual volume in the millions. The cost of the latest HC trap bypass design is approximately 5% of the original stainless steel zeolite flow through HC trap.
Journal Article

Analysis of Tool Wear for Trimming of DP980 Sheet Metal Blanks

2017-03-28
2017-01-0302
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 discuss the methodology of analyzing die wear for trimming operations of UHSS components and illustrate it with some examples of tool wear analysis for trimming 1.5mm thick DP980 steel.
Journal Article

Evaluation of Prog-Die Wear Properties on Bare DP1180 Steel

2017-03-28
2017-01-0310
The die wear up to 80,800 hits on a prog-die setup for bare DP1180 steel was investigated in real production condition. In total, 31 die inserts with the combination of 11 die materials and 9 coatings were evaluated. The analytical results of die service life for each insert were provided by examining the evolution of surface wear on inserts and formed parts. The moments of appearance of die defects, propagation of die defects, and catastrophic failure were determined. Moreover, the surface roughness of the formed parts for each die insert was characterized using Wyko NT110 machine. The objectives of the current study are to evaluate the die durability of various tooling materials and coatings for flange operations on bare DP 1180 steel and update OEM tooling standards based on the experimental results. The current study provides the guidance for the die material and coating selections in large volume production for next generation AHSSs.
Technical Paper

Fatigue Life Prediction for Adaptable Insert Welds between Sheet Steel and Cast Magnesium Alloy

2016-04-05
2016-01-0392
Joining technology is a key factor to utilize dissimilar materials in vehicle structures. Adaptable insert weld (AIW) technology is developed to join sheet steel (HSLA350) to cast magnesium alloy (AM60) and is constructed by combining riveting technology and electrical resistance spot welding technology. In this project, the AIW joint technology is applied to construct front shock tower structures composed with HSLA350, AM60, and Al6082 and a method is developed to predict the fatigue life of the AIW joints. Lap-shear and cross-tension specimens were constructed and tested to develop the fatigue parameters (load-life curves) of AIW joint. Two FEA modeling techniques for AIW joints were used to model the specimen geometry. These modeling approaches are area contact method (ACM) and TIE contact method.
Journal Article

Electrochemical Characterization of Coated Self-Piercing Rivets for Magnesium Applications

2016-01-01
2015-01-9085
This work reports on measurement and analysis of the galvanic interaction between steel self-piercing rivets (SPRs) having several different surface conditions and magnesium alloy substrates under consideration for use in automotive structural assemblies. Rivet surface conditions included uncoated steel, conventional Zn-Sn barrel plating and variations of commercial aluminizing processes, including supplemental layers and sealants. Coating characteristics were assessed using open circuit potential (OCP) measurement, potentiodynamic polarization scanning (PDS), and electrochemical impedance spectroscopy (EIS). The degree of galvanic coupling was determined using zero-resistance ammeter (ZRA) and the scanning vibrating electrode technique (SVET), which also permitted characterization of galvanic current flows in situ.
Technical Paper

MMLV: Chassis Design and Component Testing

2015-04-14
2015-01-1237
The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine resulting in a significant environmental benefits and fuel consumption reduction. As part of this project, several automotive chassis components were selected for development and evaluation on the MMLV C/D segment passenger sedan.
Technical Paper

Nondestructive Evaluation of Adhesively-Joined Aluminum Alloy Sheets Using an Ultrasonic Array

2015-04-14
2015-01-0702
Adhesive bonding technology has gained ever-increasing significance in automotive industry, especially with the growing use of aluminum (Al) alloy body structures. The variability in thicknesses of the metal and adhesive layers, as well as in joint geometry, of automotive components has presented challenges in nondestructive evaluation of adhesive joints. Though these challenges were recently overcome for steel-adhesive joints using an ultrasonic pulse-echo technique, the difference in acoustic impedances of steel and Al leads to a lack of robustness in utilizing the same algorithm for Al-adhesive joints. Here, we present the results from using a modified version of this technique to inspect Al-adhesive joints in both laboratory and production environments. A 15-MHz, 52-pixel, 10 mm × 10 mm matrix array of ultrasonic transducers was used to obtain ultrasonic pulse echoes from joint interfaces, analysis of which produced C-scan images of the adhesive bead.
Technical Paper

Application of Advanced High Strength Stainless Steel for Mass Reduction in Automotive Structures - A Front Bumper Beam Case Study

2011-04-12
2011-01-1054
The front bumper of a current production vehicle, which is made of hot-stamped 15B21 aluminized steel, was studied for mass and cost reductions using the Advanced High Strength Stainless Steel product NITRONIC® 30 (UNS Designation S20400) manufactured by AK Steel Corporation. This grade of stainless steel offers a combination of high ductility and strength, which was utilized to significantly modify the design of the bumper beam to incorporate geometry changes that improved its stiffness and strength. The structural performance of the bumper assembly was evaluated using LS-Dyna-based CAE simulations of the IIHS 40% Offset Full-Vehicle Impact at 40 mph with a deformable barrier, and the IIHS Full Width Centerline 6 mph Low-Speed Impact. Optimization of the bumper beam shape and gauge was performed using a combination of manual design iterations and a multi-objective optimization methodology using LS-Opt.
Technical Paper

Investigation of Stamping Tooling Durability for Dual Phase Steels

2011-04-12
2011-01-1060
Advanced High-Strength Steels (AHSS) have become an essential part of the lightweighting strategy for automotive body structures. The ability to fully realize the benefits of AHSS depends upon the ability to aggressively form, trim, and pierce these steels into challenging parts. Tooling wear has been a roadblock to stamping these materials. Traditional die materials and designs have shown significant problems with accelerated wear, galling and die pickup, and premature wear and breakage of pierce punches. [1] This paper identifies and discusses the tribological factors that contribute to the successful stamping of AHSS. This includes minimizing tool wear and galling/die pick-up; identifying the most effective pierce clearance (wear vs. burr height) when piercing AHSS; and determining optimal die material and coating performance for tooling stamping AHSS.
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