Tooling design and microwave curing technologies for the manufacturing of fiber-reinforced polymer composites in aerospace applications

The increasing demand for high-performance and quality polymer composite materials has led to international research effort on pursuing advanced tooling design and new processing technologies to satisfy the highly specialized requirements of composite components used in the aerospace industry. This paper reports the problems in the fabrication of advanced composite materials identified through literature survey, and an investigation carried out by the authors about the composite manufacturing status in China’s aerospace industry. Current tooling design technologies use tooling materials which cannot match the thermal expansion coefficient of composite parts, and hardly consider the calibration of tooling surface. Current autoclave curing technologies cannot ensure high accuracy of large composite materials because of the wide range of temperature gradients and long curing cycles. It has been identified that microwave curing has the potential to solve those problems. The proposed technologies for the manufacturing of fiber-reinforced polymer composite materials include the design of tooling using anisotropy composite materials with characteristics for compensating part deformation during forming process, and vacuum-pressure microwave curing technology. Those technologies are mainly for ensuring the high accuracy of anisotropic composite parts in aerospace applications with large size (both in length and thickness) and complex shapes. Experiments have been carried out in this on-going research project and the results have been verified with engineering applications in one of the project collaborating companies

Achievements with model-based development on the innovative traction system of the AMBER-ULV Car

A traction system based on a dual-axle, dual-motor, dual-battery configuration is pro-posed for the AMBER-ULV car. Advantages of this solution and design criteria for maximizing performance in the whole speed range are given. A unique traction control system capable of generating the torque reference for both drive is also given

Exploring different vehicle model complexity for reference in a sensor signal processing model controller

Vehicle handling and stability performances are of great importance high performance sport cars. To reach these targets, very high standards of performance all the more prestigious vehicle companies have improved a lot the kinematics and compliance of the front and rear suspensions, together with the tire characteristics development. Normally the improvements have been obtained working on existing suspensions without adding any active systems able to change the suspension kinematics and compliances. The only exception has been some suspension rework of 4 wheel steering system studied in the early 80ies years, that is an active system able to change the toe angle of the rear suspension wheels. This solution has not obtained a significant success also in the market of very prestigious cars because could not reach the target performance improvement of driving requested by the customer. The proposed research work is innovative because instead to change actively the wheel toe angle it applies a solution to change the wheel camber angle through the geometry of the rear suspension. The proposed system uses two separated electro mechanical actuators, one per wheel, in place of two existing rear suspension links. A Sensor Signal Processing Model has been developed to estimate the vehicle states and calculating tire-road contact forces and vehicle sideslip angle. The methodological approach uses the equations of motion of the chassis applying the fundamental principles of classical physics: Newtonian method and Euler angles. In parallel a 15 dof (degrees of freedom) preview vehicle model has been used to achieve a high fidelity simulation vehicle dynamics. The selected software is LMS.Amesim to handle complex real-time 3D-1D mechatronic systems without any simplified conceptual models. The vehicle control logic is based on the continuous updating of the preview vehicle model by the controller sensors information network, which makes the model forecast behaviour closer to the real one and improve comfort and linearity of the vehicle response

Roll center position and active control of rear suspension geometry

In modern sporty luxury cars it is becoming more and more important to control the body and wheel motions. This is necessary first to increase the driver feeling of car control and second, even more important reason, to increase safety and performances. The basis of kinematic body and wheels movements is strictly connected to the ssumption that the vehicle body roll about a kinematic roll axis. When a car corners, the tires react to the centrifugal force at the center of gravity. This lateral force can be translated to the roll center with appropriate forces and moments. The amount of body roll in a corner depends on the position of the roll axis relative to the car center of gravity. The closer the roll axis is to the center of gravity, the less the body will roll