The aim of a research project was to develop a system for the analysis, processing and addressing of data flows of process-integrated 3D-measurements of magnesium workpieces for car body construction and its prototypical application. By applying optical measuring methods for quality control and using object-specific measurement for process control, considerable savings of energy and other resources can be achieved in automotive engineering. The QM standards for measuring systems for forming processes in the automotive sector place high demands on accuracy and measuring speed. By using multi-camera systems, clock rates of less than 10 seconds and accuracies of 30-40 µm over the entire measuring range can be guaranteed. The modular design of a system facilitates process integration due to the relatively low effort required for different manufacturing tasks. The performance analysis of the measuring system and the process landscape design were carried out.
This SAE Recommended Practice provides minimum performance target and uniform laboratory procedures for fatigue testing of wheels and demountable rims intended for normal highway use on trucks, buses, truck-trailers, and multipurpose vehicles. Users may establish design criteria exceeding the minimum performance target for added confidence in a design. The cycle target noted in Tables 1 and 2 are based on Weibull statistics using two parameter, median ranks, 50% confidence level and 90% reliability, and beta equal to two, typically noted as B10C50. For other wheels intended for normal highway use and temporary use on passenger cars, light trucks, and multipurpose vehicles, refer to SAE J328. For wheels used on trailers drawn by passenger cars, light trucks, or multipurpose vehicles, refer to SAE J1204. For bolt together military wheels, refer to SAE J1992. This document does not cover other special application wheels and rims.
This paper clarified the dynamic impact of automated bus on asphalt pavement by taking an innovative bus using automation technology as a case study. Firstly, main distresses caused by automated bus on roads were investigated. On this basis, a three-dimensional finite element model that considers the vehicle type and driving conditions of automatic bus was established.
Heat exchangers are a prolific application found in all things that concern fluid and power; they are mission-critical applications that affect overall performance in aircraft of all sizes. Yet, for years, heat exchangers have been constrained, by traditional manufacturing, in terms of limited geometric freedom and lengthy lead times. Consider the following • Heat exchangers are commonly fabricated with stainless steel and then gold brazed, which can be extremely costly • Each weld joint costs $100; in traditionally manufactured fuel and high-pressure systems, there could be hundreds of welds • There can be a lack of integration with other systems like electrical motors or conformal cooling with batteries. Assembly integration, testing, and validation are lengthy and difficult. Additive manufacturing (aka 3D printing) has opened new possibilities for thermal conductivity and heat-exchanger design that enable end users to push the limits of what is possible.
Moderator - Xiaobo Yang, Oshkosh Corporation Panelists - Mehdi Ahmadian, Virginia Tech. Neil Bishop, CAEfatigue, Ltd. Ram Iyer, ArcelorMittal This technical panel focuses on innovative and improved durability development, analysis methodologies, and problem-solving techniques in the commercial and military vehicle industry. The subjects of interest include: studies and discussion on (1) duty cycle development and customer usage correlation; (2) fatigue of metallic and non-metallic materials (3) environmental effects on fatigue performance (4) effect of manufacturing processes and operating condition uncertainties on durability performance, and (5) durability performance validation and testing methodologies.
Earlier publications show that brake pad physical properties such as hardness, modulus and natural frequencies continue to increase at room temperature over a period of 12 months and that the changes are faster during the first 3 - 6 months. The current investigation was undertaken to see how the properties might change during testing for the pads as well as for the discs. Low-copper and copper-free formulations were tested on pickup truck and passenger car brakes. In all cases, the dynamic modulus and natural frequencies are found to decrease (not increase) after the SAE J2522 performance testing, indicating that the stiffness of the pad and that of the disc decrease faster than the mass loss due to wear. Also, the inboard pad and the outboard pad change at two different rates.
Commercial heavy truck drum linings of 4 different compositions were tested using the Chase tester under constant loads and temperatures at a constant speed in order to find out how lining wear might affect the friction coefficient. When the lining wear increases, the friction coefficient increases linearly under a condition of constant load, speed and temperature. However, when the lining wear approaches zero, the friction coefficient still remains relatively high, indicating other factors are also involved in controlling friction such as interface deformation and others. As the temperature increases or the load increases, the wear contribution to the friction becomes less and less effective. All these observations are discussed and explained in terms of wear particle formation and friction film behavior.