Sensor Networks for Integration into Textile-Reinforced Composites
The integration of sensor networks into textile-reinforced composites enables monitoring of different physical values like strain, acceleration and temperature in a component. This paper presents a system concept of a modular sensor network supporting different sensor types and the wireless transmission of stored measurements. Sensor and transponder ASICs have been developed for realizing first demonstration examples. The feasibility of integration of discrete components and silicon chips was successfully verified in experiments with a composite made of glass fibers and polypropylene. Two demonstrators with fully functional integrated modules were fabricated in order to show the possibility of integrated strain monitoring and recording of impact events with wireless data transmission.
Development of a remote impact damage identification system
In this paper, an impact damage identification approach is proposed. Based on this approach, a remote impact damage identification system has been developed. The remote identification system consists of hardware and software. The hardware consists of a carbon‐fiber‐reinforced plastic (CFRP) plate with four surface‐mounted piezoelectric sensors, a digital oscilloscope, a local network, a wireless LAN card, and a notebook computer. The software includes a source location algorithm based on fast wavelet transform and an impact load identification algorithm based on impact response inverse analysis. The piezoelectric sensors can detect Lamb wave signals generated by impact load without any amplification. The source location algorithm can reduce the influence of noise in the Lamb wave signals. When the CFRP plate is impacted, the oscilloscope promptly records the impact response signals detected by the mounted piezoelectric sensors, and the computer simultaneously receives the signals via the local network and wireless LAN card from the oscilloscope. The system can remotely identify the impact position and the impact load history with good precision in real time. Copyright © 2005 John Wiley & Sons, Ltd.
Proposition of Simple Identification Method for Multiple Impact Forces on Orthotropic Laminated Plates.
In this paper we propose a simple method for identification of multiple impact forces on a simply supported orthotropic laminated plate. Acceleration responses at several points in the interior of the plate are measured in order to determine locations and histories of the impact forces. The present method can identify the impact forces at any arbitrary locations of the plate with every measurement of acceleration. First, the identification algorithm is shown for single and double impact forces at arbitrary locations on the plate. Next, through the numerical examples we examine the effect of the number of measurement points on the identified results and the measurement errors are also taken into consideration in the identification. The validity of the present method is shown by comparing the present results with exact ones for locations and histories of impact forces.