Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

2005 Ford GT Magnesium Instrument Panel Cross Car Beam

2005-04-11
2005-01-0341
Ford GT 2005 vehicle was designed for performance, timing, cost, and styling to preserve Ford GT40 vintage look. In this vehicle program, many advanced manufacturing processes and light materials were deployed including aluminum and magnesium. This paper briefly explains one unique design concept for a Ford GT instrument panel comprised of a structural magnesium cross-car beam and other components, i.e. radio box and console top, which is believed to be the industry's first structural I/P from vehicle crash load and path perspectives. The magnesium I/P design criteria include magnesium casting properties, cost, corrosion protection, crashworthiness assessments, noise vibration harshness performance, and durability. Magnesium die casting requirements include high pressure die cast process with low casting porosity and sound quality, casting dimensional stability, corrosion protection and coating strategy, joining and assembly constraints.
Technical Paper

A Benchmark Test for Springback Simulation in Sheet Metal Forming

2000-10-03
2000-01-2657
Springback is a serious problem in sheet metal stamping. It measures the difference between the final shape of the part and the shape of the forming die. Sheet metal forming simulation has made significant progress in predicting springback and several computer simulation codes are commercially available to predict and compensate for it in tool design. The accurate prediction of springback is important and there is a need to validate and verify those predictions with experimental results. Current validation techniques lack standardized procedures, require measurement fixtures that may impose unrealistic restraint on the part, require profiling equipment such as CMM or laser scanning and for the most part produce small springback which reduces measurement accuracy and increases experimental error. A benchmark test has been developed which addresses all these concerns and compares springback predictions by various numerical simulation codes with each other and with experimental results.
Technical Paper

A Benchmark Test for Springback: Experimental Procedures and Results of a Slit-Ring Test

2005-04-11
2005-01-0083
Experimental procedures and results of a benchmark test for springback are reported and a complete suite of obtained data is provided for the validation of forming and springback simulation software. The test is usually referred as the Slit-Ring test where a cylindrical cup is first formed by deep drawing and then a ring is cut from the mid-section of the cup. The opening of the ring upon slitting releases the residual stresses in the formed cup and provides a valuable set of easy-to-measure, easy-to-characterize springback data. The test represents a realistic deep draw stamping operation with stretching and bending deformation, and is highly repeatable in a laboratory environment. In this study, six different automotive materials are evaluated.
Technical Paper

A CAE Study on Side Doors Inner Panel Deflection under Glass Stall Up Forces

2017-11-07
2017-36-0205
Not only well-functioning, but also the way operating everyday items "feel", gauges costumer perception of an automobile robustness. To prevent costumer dissatisfaction with door trim panel movement when operating power windows, deflections must be kept small. Deflections of inner panel are seen through trim panel and are responsible for giving a flimsy idea of the door. In this paper, inner panel movement for a fully stamped door in full glass stall up position is analyzed. Through CAE analyses, inner panel behavior was compared, considering different types of reinforcement for belt region.
Technical Paper

A Comparative Investigation on the High Temperature Fatigue of Three Cast Aluminum Alloys

2004-03-08
2004-01-1029
The high temperature fatigue behaviors of three cast aluminum alloys used for cylinder head fabrication - 319, A356 and AS7GU - are compared under isothermal fatigue at room temperature and elevated temperatures. The thermo-mechanical fatigue behavior for both out-of-phase and in-phase loading conditions (100-300°C) has also been investigated. It has been observed that all three of these alloys present a very similar behavior under both isothermal and thermo-mechanical low-cycle fatigue. Under high-cycle fatigue, however, the alloys A356 and AS7GU exhibit superior performance.
Technical Paper

A Comparative Study of Dent Resistance Incorporating Forming Effects

2005-04-11
2005-01-0089
Dent resistance is an important attribute in the automotive panel design, and the ability to accurately predict a panel's dentability requires careful considerations of sheet metal properties, including property changes from stamping process. The material is often work-hardened significantly during forming, and its thickness is reduced somewhat. With increased demand for weight reduction, vehicle designers are seriously pushing to use thinner-gauged advanced high-strength steels (AHSS) as outer body panels such as fenders, hoods and decklids, with the expectation that its higher strength will offset reduced thickness in its dentability. A comparative study is conducted in this paper for a BH210 steel fender as baseline design and thinner DP500 steel as the new design.
Technical Paper

A Comprehensive Study of Door Slam

2004-03-08
2004-01-0161
As part of an ongoing technical collaboration between Ford and Rouge Steel Company, a comprehensive study of door slam event was undertaken. The experimental phase of the project involved measurements of accelerations at eight locations on the outer panel and strains on six locations of the inner panel. Although slam tests were conducted with window up and window down, results of only one test is presented in this paper. The CAE phase of the project involved the development of suitable “math” model of the door assembly and analysis methodology to capture the dynamics of the event. The predictability of the CAE method is examined through detailed comparison of accelerations and strains. While excellent agreement between CAE and test results of accelerations on the outer panel is obtained, the analysis predicts higher strains on the inner panel than the test. In addition, the tendency of outer panel to elastically buckle is examined.
Technical Paper

A Development Procedure to Improve the Acoustical Performance of a Dash System

2005-05-16
2005-01-2515
This paper discusses a development procedure that was used to evaluate the acoustical performance of one type of dashpanel construction over another type for a given application. Two very different constructions of dashpanels, one made out of plain steel and one made out of laminated steel, were studied under a series of different test conditions to understand which one performs better, and then to evaluate how to improve the overall performance of the inferior dashpanel for a given application. The poorly performing dashpanel was extensively tested with dashmat and different passthroughs to understand the acoustic strength of different passthroughs, to understand how passthroughs affect the overall performance of the dash system, and subsequently to understand how the performance can be improved by improving one of the passthroughs.
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.
Journal Article

A Path Independent Forming Limit Criterion for Sheet Metal Forming Simulations

2008-04-14
2008-01-1445
A new strain-based forming limit criterion is proposed to assess the localized necking failure for sheet metal forming simulations when deformation paths deviate significantly from linearity. Different from the traditional strain-based Forming Limit Diagrams (FLD) in terms of major and minor strains, the new FLD is constructed based on effective strains and material flow direction at the end of forming. This new criterion combines the advantages of stress-based FLD for its path-independence and the traditional linear strain path FLD for its easy interpretation. The proposed FLD is validated through both theoretical prediction with Marciniak-Kuczynski (M-K) model and available experimental data in literature, and its relationship with stress-based FLDs is discussed.
Technical Paper

A Practical Approach to Consider Forming Effects for Full Vehicle Crash Application

2009-04-20
2009-01-0471
The forming effects along with strain rate, actual material properties and weld effects have been found to be very critical for accurate prediction of crash responses especially the prediction of local deformation. As a result, crash safety engineers started to consider these factors in crash models to improve the accuracy of CAE prediction and reduce prototype testing. The techniques needed to incorporate forming simulation results, including thickness change, residual stresses and strains, in crash models have been studied extensively and are well known in automotive CAE community. However, a challenge constantly faced by crash safety engineers is the availability of forming simulation results, which are usually supplied by groups conducting forming simulations. The forming simulation results can be obtained by either using incremental codes with actual stamping processes or one-step codes with final product information as a simplified approach.
Technical Paper

A Simplified Method to Make Temperature Measurements of a Metal Surface using the Surface as One Component of Thermocouple

2008-04-14
2008-01-0918
Instrumentation of an exhaust system to measure surface temperature at multiple locations usually involves welding independent thermocouples to the surface of the system. This report describes a new type of thermocouple fabricated to measure temperature at a point or temperature difference between points on a metallic object utilizing the metal as one component of the new thermocouple. AISI 316 stainless steel is used in the current study to represent automotive exhaust pipe. The other component of the thermocouple is Nickel-Chromium (Chromel, Chromega), one of the two metals used in type K thermocouples, which are generally used for exhaust temperature measurements during emission tests. Use of the new thermocouple is contingent upon an accurate calibration of its response to changes in temperature.
Technical Paper

A Test Method for Quantifying Residual Stress Due to Heat Treatment in Metals

2006-04-03
2006-01-0319
Quantification of residual stresses is an important engineering problem impacting manufacturabilty and durability of metallic components. An area of particular concern is residual stresses that can develop during heat treatment of metallic components. Many heat treatments, especially in heat treatable cast aluminum alloys, involve a water-quenching step immediately after a solution-treatment cycle. This rapid water quench has the potential to induce high residual stresses in regions of the castings that experience large thermal gradients. These stresses may be partially relaxed during the aging portion of the heat treatment. The goal of this research was to develop a test sample and quench technique to quantify the stresses created by steep thermal gradients during rapid quenching of cast aluminum. The development and relaxation of residual stresses during the aging cycle was studied experimentally with the use of strain gauges.
Technical Paper

Advanced High Strength Steels for Chassis Structures

2008-04-14
2008-01-0854
Even though the use of AHSS such as DP590 for body structure applications is becoming relatively common among automobile manufacturers, application of AHSS for chassis structures is relatively new. Chassis structures such as frames and sub-frames typically use hot rolled steel grades in the yield strength range of 220 MPa to 250 MPa. For body-on-frame vehicles, the primary load carrying and energy absorbing structure is the frame. Therefore, hot rolled AHSS such as HR DP590 would be key enablers for weight reduction and strength enhancement of these structures. This paper presents a case for developing AHSS grades for chassis structures, some of the challenges for implementing them, and related work done at Ford Motor Company.
Technical Paper

Aluminum Vehicle Side Impact Design, Test and CAE

2002-03-04
2002-01-0249
Ford designed and built a midsize family sedan for the PNGV (Partnership for a New Generation of Vehicle). The side impact performance of the aluminum vehicle and the current CAE capability was studied. The vehicle was tested according to the specifications of FMVSS 214. The results show the vehicle meet the federal safety requirements. The impact performances of the front and rear dummies were comparable to those of the steel counterpart. CAE analysis was conducted to develop the body component design and to predict the structural and dummy responses. The results show that without modeling of the joint (rivet and weld) separation, the accuracy of the CAE crash analysis for this aluminum vehicle was inadequate. When empirical separation criteria were incorporated to model the joint, analysis results correlated with the test. Further development of robust modeling methods for joint separation is needed to improve the prediction of aluminum structure crash responses.
Technical Paper

An Obliquely Incident X-Ray Radiography to Measure Greatest Corrosion Depths in Automobile Metallic Plates

2003-03-03
2003-01-1241
An obliquely incident X-ray radiography was developed to measure the greatest depths, orientations and locations of corrosion pits in automobile metallic plates. This technique can also be used on-site for components in use. The corrosion depth profile and the greatest depth can be calculated with the established relations. A 3-D rotational microscope and surface profiler were utilized to evaluate the sensitivities and accuracies of the technique for aluminum and steel plates, respectively.
Technical Paper

An Optimization Model for Reallocating Stamped Parts

2017-03-28
2017-01-0244
We describe an optimization model developed by Ford Motor Company to reallocate stamped parts between facilities when business conditions change. How can the business meet new targets when demand starts to exceed existing capacity? Likewise, how can it respond when demand is lower than expected? Sometimes the business can reduce costs by transferring production to a different location or by outsourcing parts. We describe in this paper how mathematical optimization can identify solutions that balance both logistical and outsourcing costs. We explain the algorithm and demonstrate with a small example how it recommends sourcing plans that minimize cost.
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.
Technical Paper

Analytical & Experimental Study of Component Level Crash Performance of DP 600 Steel

2006-04-03
2006-01-1587
Advanced High Strength Steels such as Dual Phase 600 (DP600) are gaining popularity in automotive body structure applications. Given their higher strength, the efficacy of Advanced High Strength Steels for intrusion resistance applications is relatively well accepted. On the other hand, use of Advanced High Strength Steels for energy absorption applications needs to be studied and understood on a case-by-case basis. Based on stress-strain characteristics, one would expect DP600 as a material to have better energy absorbing characteristics than conventional High Strength Steel such as HSLA350 (High Strength Low Alloy Steel) that has comparable yield strength. However, as the energy absorption at the component and system level, in addition to material properties, depends on geometry, as well as manufacturing and assembly related factors, a study was conducted to compare the component level energy absorption characteristics of DP600 and HSLA350 parts.
Technical Paper

Analytical Crush Resistance of Hybrid Aluminum-RCM Roof Structures

2000-03-06
2000-01-0066
The crush resistance of roof structures is critical to minimizing injuries and enhancing occupant survival during rollover crashes. Federal Motor Vehicle Safety Standard FMVSS 216 requires the roof structure to resist a load equal to one and one half (1&1/2) the unloaded weight of the vehicle during the first 127 millimeters (five inches) of deformation. This paper discusses the analytical methodologies applied and challenges encountered developing a hybrid Aluminum-Random Chop Material (RCM) roof structure. The roof structure materials are extruded 6260T6 aluminum and RCM. This hybrid roof structure has to satisfy not only the FMVSS 216 roof crush resistance, but also packaging, torsional stiffness and head impact requirements. Due to packaging constraints, the structure has to be developed without the roof bow at the B-pillar level.
X