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The detailed analysis of the tire loading and the subsequent deformations under operational driving conditions is of great importance for the basic investigation of the functionability as well as for the input and verification of the computer simulation of tires. Such data are also required for the definition of mission profiles as well as for the derivation of programs for the durability approval. The principles for the measurement of global tire deformations by spring loaded deflection transducers arranged in-between the tire crown and the rim are described. By combination of those sensors with wheel force transducers the determined tire deformations are referred to the actual service loading conditions. The sensors and transducers are described and examples of field measurement on heavy truck tires under distinguished driving conditions are presented.

The durability approval of truck axles is performed on proving grounds with well defined road characteristics as well as in laboratory test facilities simulating these loading conditions. These proof out tests are supposed to reproduce within a reasonable time the customer usage conditions which are expected during the life of a vehicle taking into account the large scatter of service. The programs and requirements are based on extensive measurements as well as long term experience. However, the development of vehicles for specific mission profiles as well as the introduction of components from new light weight material and innovative manufacturing technologies with different durability properties, requires procedures for the evaluation of the programs themselves. Within this paper the procedure of a comparative damage evaluation of test track and laboratory test programs with respect to an appropriated mission profile is demonstrated as example on a truck axle.

Experience from several car projects shows that S-N curves for spot welds generated under load control in the high cycle fatigue regime might be very conservative when used in the low cycle fatigue regime. Therefore, force and displacement controlled low cycle fatigue tests were carried out on peel and shear loaded specimens. Both constant (CA) and variable amplitude (VA) load signals were used. Finally, a method for predicting fatigue life of spot welds with increased accuracy in the low cycle fatigue regime is proposed. The method is simple, fast and accurate and can be used together with linear finite element analysis (FEA) and existing fatigue packages.

The design and validation process of a new car requires detailed knowledge of the interaction of dynamic forces and moments introduced into the rotating wheel. These forces are measured under operating conditions with appropriate sensors and transducers. Due to the effects of the dynamic masses, the loads should be sensed as close to the tire/road interface as possible using a wheel load transducer. Currently, existing transducers are quite heavy, not very accurate and elaborate calibrations and computations have to be performed. With the newly developed VEhicle LOad Sensor (VELOS), these deficiencies are overcome. Examples of dynamic force and moment calibrations with the original tire are presented, as well as road load data acquisitions comparing results from the VELOS with those of the axle transducers on a passenger car under different driving maneuvers.

Engine management systems combined with fuel injectors allow a precise fuel metering for a robust combustion process. Stricter emission legislations increase the requirements for these port fuel injection systems (PFI), whereas the price is still the main driver in the emerging low cost 2-wheeler market. Therefore, a holistic mechatronic approach is developed by Bosch, which allows an improved fuel metering over life time and furthermore provides new possibilities for diagnosis without changing the injector itself. This example of an intelligent software solution provides the possibility to further improve the accuracy of the fuel metering of an injector. By use of the information contained in the actuation voltage and current, the opening and closing times of the injector are derivable.

The durability and the life of spot welded sheet metal structures are mainly controlled by the strength of the joints. Designers are aiming at reliable information, already in early design phase, that the weld spots will indeed perform satisfactorily throughout the required life cycles of a complex structure under the operational loading conditions. Consequently, a theoretical approach for the determination of the structural durability and the reliable design and optimization of spot welded components has been developed and extensively verified for serial components by theoretical analysis and tests. The method starts with Finite-Element-computations of the structures in the design stage and strength data obtained from component-like specimens; both are commonly available in the design phase, but are not sufficient for the determination of the structural integrity.