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In this study, the Gleeble test was used to investigate the effect of cooling time, which is an indication of welding heat input, on fracture toughness at the simulated HAZ of different test materials, including one mild steel and three DP600 steels from three different suppliers. One of the important findings is that the three DP600 steels have similar tensile properties and similar base metal microstructures. After different simulated welding thermal cycles, however, the microstructure, the microhardness and thus the fracture toughness of the simulated HAZ of the steels showed significant variations among the steels tested, which indicates that DP600 steels from different suppliers can have different responses to the welding heat input.

Programmable vehicle models (PVMs) are intended to save time and costs in building bucks to evaluate vehicle interior packages. This paper presents results from a series of three studies conducted to determine the applicability and limitations of the methodology of using a PVM. The PVM used for the study was built by Prefix Corporation and has forty-two axes of adjustments. The first study verified the PVM's ability to reproduce dimensions. It showed that the PVM was acceptably accurate, with most dimension measurement ranges less than 2-3 mm. The second study was conducted to determine if subject responses are reliable indicators of package differences. Aside from some special causes, most were found to be. The third study was conducted to determine how well the PVM replicated 3 actual vehicles. Despite some dimensional discrepancies, there was evidence of correlation between subject responses from the PVM and actual vehicles.

MIG weld failures are commonly seen in chassis and frame structures in automobile industry. Until now, testing and CAE analysis based on local stresses in the vicinity of MIG weld were driving the design of these welds. With the advent of advanced methods and tools, it is possible to estimate fatigue life of MIG welds and support the design in the early stages of the vehicle program. Recently, fatigue damage models are developed for assessing the durability of MIG welds in aluminum auto structures. These damage models are based on advanced technologies like mesh-insensitive structural stress method, virtual node method, estimation of notch stress intensities and life predictions based on two-stage crack growth law. This paper outlines the theoretical aspects involved in deriving the master S-N curve.

Six-Sigma provides the opportunity and discipline to eliminate mistakes, improve morale, and save money. Doing things right and keeping them consistent is the idea behind Six-Sigma. A fundamental objective of Six-Sigma is to achieve customer satisfaction with continuous improvement in quality. Process control and manufacturing variation reduction is important but companies often find that the majority of their quality problems were actually created during the design process. An example of improving manufacturing process capability to give bottom line cost savings and customer satisfaction is presented in this paper. The methodology to increase system robustness through Design for Six Sigma (DFSS) is presented and demonstrated through the extension of the case study of crankshaft journal lobing design robustness improvements.

One thing that is very important in a carmaker company is its know-how built during all its life. Such an experience allows, for instance, to correlate the customer expected product life with accelerated tests procedures. When it comes to cars, it is usual to have correlated proving routes in such way that if a prototype can take a number of passing in the proving ground without failure, it is unlikely the car is going to fail during a regular life. In the other hand, if a failure at determined percentage of the test happens, it is predictable that the same failure shows up at the same percentage of the product design life. This paper proposes a methodology based on the SxN fatigue theory to solve durability issues observed in correlated durability tests.

There are many different vibration sources in a car. Engine, gears, road roughness, impacts against the wheels cause vibration and sound that can decrease the parts and the car durability as well as affect drivability, safety and passengers and community comfort. In 4×4 cars, some extra vibration sources are the parts responsible for transmitting the torque and power to the rear wheels. Each of them has their own vibration modes, excited mostly by its imbalance or by the second order engine vibration. The engine vibration is a very well known phenomena and the rear driveshaft is designed not to have any vibration mode in the range of frequencies that the engine works or its second order. The imbalance of a driveshaft is also a design requirement. That means, the acceptable imbalance of the driveshaft is limited to a maximum value.

Design for Six Sigma (DFSS) is a systematic process and a disciplined problem prevention approach to achieve business excellence. Robust design is the heart of DFSS. To enable the success of robust parameter design, one should start with good design concept. Axiomatic Design, a fundamental set of principles that determine good design practice, can help to facilitate a project team to accelerate the generation of good design concept. Axiomatic Design holds that uncoupled designs are to be preferred over coupled design. Although uncoupled designs are not always possible, application of axiomatic design principles in DFSS presents an approach to help DFSS team focus on functional requirements to achieve design intents and maximize product reliability. As a result of the application of axiomatic design followed by parameter design, the DFSS team achieved design robustness and reliability. A hydraulic lash adjuster case study will be presented.

“Doing the right things” is important for a company to stay in business while developing the right products to satisfy customers and make profits. Design for Six Sigma (DFSS) is a disciplined problem prevention approach and a systematic process to prevent defects in what is important to the customer. This paper builds on the rationale and opportunities presented in the SAE paper of Six Sigma Disciplines in Automotive Applications for improving design robustness. The methodology to increase system robustness through DFSS is presented and demonstrated through the extension of the case study of crankshaft journal lobing design robustness improvements realized from the traditional DMAIC Six Sigma project presented in the SAE paper of Six Sigma Disciplines in Automotive Applications.

In the early days of the automotive industry, durability and reliability were hit or miss affairs, with end-users often being the first to know about any durability problems - and in many cases forming an essential part of the development process. More recently, automotive companies have developed proving ground and laboratory test procedures that aim to simulate typical or severe customer usage. These test procedures have been used to develop the products through a series of prototypes and to prove the durability of the product prior to release in the marketplace. Now, commercial pressures and legal requirements have led to increasing reliance on CAE methods, with fatigue life prediction having a central role in the durability engineering process.

Considering that the sport cars versions are normally derived from medium car segment, the big challenge in this program was to transform one subcompact in a real sport car. With the focus at the consumer that looks for performance and enjoys sporty driving in conjunction with project financials and competition data the preliminary content was established together with all involved areas, Marketing, Finance, Manufacturing and Quality. Based on the items that indicate high performance, the items considered mandatory or desired by the customer and items detected by Quality research including internal indicators and external indicators, ICCD (Intensified Customer Concern Definition) and TGW (Things Going Wrong), the content was developed in three main directions towards Customer Satisfaction, I) Characterize the vehicle as a high performance car, a pure sport car with outstanding performance for power train, suspensions and brakes mainly.

The Prius, Toyota Motor Corporation’s mass-produced hybrid vehicle (HV), was launched in Japan, other Asian countries, North America and Europe, and has now been accepted into the global market. Following the Prius, the Estima Hybrid and the Crown Mild Hybrid, although being based on different systems were released into the Japanese market in 2001. Over 100,000 Toyota HVs are currently on the road, and this proves that HVs are considered practical and reliable vehicles, not special vehicles. HVs have advantages in fuel economy and exhaust gas emissions compared with conventional ICE vehicles. HVs with differing kinds of hybrid systems will be introduced into the market in the future, and will gain in popularity coexisting with ICE vehicles.

Six Sigma is a comprehensive and flexible methodology for achieving, maintaining, and maximizing business success by sustaining a disciplined use of facts, data, and statistics while managing, improving, and reinventing business processes based on customer requirements and cost targets. Six Sigma is a holistic approach to reducing concerns tied directly to achieving organizational objectives. AutoAlliance uses structured processes based on problem-solving methodologies known as D-M-A-I-C: define - measure - analyze - improve - control. Six Sigma deployment involves hard work, frustration, starts/stops, and disappointments that go along with launching a long-term culture change. AutoAlliance's goal is to have the entire workforce utilizing the methodologies in their everyday work. At that point, the “Six Sigma” change is complete.

The basic concept of the Toyota mild hybrid system is to provide a smooth and reliable engine restarting method from an idling stop, while at the same time being able to drive all of the accessories during the idling stop. This concept has been realized and marketed for the first time in the world, by utilizing a newly developed simulation of belt behavior to optimize the specification of the belt and its peripheral parts.

This paper discusses a Design For Six Sigma (DFSS) approach to a driveline system NVH design process as used on a RWD IRS (Independent Rear Suspension) vehicle program. It is shown how this approach helped understand the ways variability in the driveline system (mount properties and locations) affected output to the rest of the vehicle. A series of CAE and DFSS tools were used to deliver a distribution that described the vehicle Driveline Roughness performance, to identify the critical control factors that affected the performance, and to reduce the response sensitivity to variability of these critical factors. Other driveline issues were factored into the process indirectly.

With interest in improving vehicle quality and customer satisfaction, Ford Motor Company initiated an effort aimed at improving dent resistance of closure panels. An investigation of various means of product improvement led to the recognition of dual phase steels, due to their inherent formability and strain hardening attributes, as the most appropriate steel panel for outer panel applications. Ispat Inland's new Electro-galvanized dual phase steel DI-FORM 500 (henceforth referred to by the generic designation, DP500), which meets 500 MPa minimum tensile strength, was specifically designed to meet automotive exposed quality standards. This paper compares the dent resistance performance of automotive door assemblies manufactured with both Bake Hardenable 210 (BH210) and DP500 door outer panels. Results indicate the achievement of significantly improved outer panel dent resistance through the use of the DP500 product.

In most aspects of mechanical design related to a motor vehicle there are two ways to treat dynamic fatigue problems. These are the time domain and the frequency domain approaches. Time domain approaches are the most common and most widely used especially in the automotive industries and accordingly it is the method of choice for the fatigue calculation of welded structures. In previous papers the frequency approach has been successful applied showing a good correlation with the life and damage estimated using a time based approach; in this paper the same comparative process has been applied but now extended specifically to welded structures. Both the frequency domain approach and time domain approach are used for numerically predicting the fatigue life of the seam welds of a thin sheet powertrain installation bracketry of a commercial truck submitted to variable amplitude loading. Predicted results are then compared with bench tests results, and their accuracy are rated.

Designing a durability test for an automatic transmission that appropriately reflects customer usage during the lifetime of the vehicle is a formidable task; while the transmission and its components must survive severe usage, overdesigning components leads to unnecessary weight, increased fuel consumption and increased emissions. Damage to transmission components is a function of many parameters including customer driving habits and vehicle and transmission characteristics such as weight, powertrain calibration, and gear ratios. Additionally, in some cases durability tests are required to verify only a subset of the total parameter space, for example, verifying only component modifications. Lastly, the ideal durability test is designed to impose the worst case loading conditions for the maximum number of internal components, be as short as practicable to reduce testing time, with minimal variability between tests in order to optimize test equipment and personnel resources.

Many studies have been conducted and supporting literature has been published to better understand thermal comfort for the automotive environment, particularly, for the HVAC system within the cabin. However, reliable assessment of occupant thermal comfort for seating systems has lacked in development and understanding. Evaluation of seat system performance in terms of comfort has been difficult to quantify and thus most tests have been established such that the hardware components are tested to determine if the thermal feature does no harm to the customer. This paper evaluates the optimal seat surface temperature range to optimize human thermal comfort for an automotive seating system application for heated and ventilated seats.

Onboard, embedded cellular modems are enabling a range of new connectivity features in vehicles and rich, real-time data set transmissions from a vehicle’s internal network up to a cloud database are of particular interest. However, there is far too much information in a vehicle’s electrical state for every vehicle to upload all of its data in real-time. We are thus concerned with which data is uploaded and how that data is processed, structured, stored, and reported. Existing onboard data processing algorithms (e.g. for DTC detection) are hardcoded into critical vehicle firmware, limited in scope and cannot be reconfigured on the fly. Since many use cases for vehicle data analytics are still unknown, we require a system which is capable of efficiently processing and reporting vehicle deep data in real-time, such that data reporting can be switched on/off during normal vehicle operation, and that processing/reporting can be reconfigured remotely.

The development costs that new design requires are subject to everyday discussions and saving opportunities are mandatory. Using CAE to predict design changes can avoid excessive costs with prototypes parts, considering the high reliability those current mathematical models can provide. This paper presents the methodology used during the development of a parabolic leaf spring for the rear suspension of a commercial truck, considering mainly the parabolic profiles and stress distribution on the leaves, calculated using CAE software (ANSYS) and experimental tests to measure the actual stress on each leaf, certifying the correlation between computational calculations and real stress on the parts during bench and vehicle evaluations.