Proc. of the IEEE International Conference on Smart Instrumentation, Measurement and Applications (ICSIMA) 26-27 November 2013, Kuala Lumpur, Malaysia 978-1-4799-0843-1/13/$31.00 ©2013 IEEE Flatbed Scanner Image and Single Ultrasonic Rangefinder Technique for Composite Laminates Defect Detection M. F. Mahmod 1 , M. Z. Mohamed Pauzi 2 , Elmi Abu Bakar 3 School of Mechanical Engineering, Universiti Sains Malaysia 14300 Nibong Tebal, Pulau Pinang, Malaysia 1 mfaisal@uthm.edu.my * School of Aerospace Engineering, Universiti Sains Malaysia 14300 Nibong Tebal, Pulau Pinang, Malaysia 2 muhdzaim90@gmail.com 3 meelmi@eng.usm.my Abstract —Inspection of composite laminates in production line using Ultrasonic C-scan for NDT requires a competent and experience inspector in order to analyze the signal which involve various technical instruction. In this paper, two approaches had been used which are image based approach and signal based approach of ultrasonic C-Scan method for NDT of composite laminate are developed and applied, with the aim to compare and validate both techniques instead of surface defect percentage area. The idea is, to propose an image analysis technique which easy to handle by general worker either the defect percentage area between the image and signal analysis are acceptable range or not. Composite laminates 6 plies which produced in-house with geometry 280 mm length x 80 mm width x 2 mm thickness was drilled to consider as defect area. Then, further analysis was performed using image scanning and processing to calculate the percentage of the defect area before we proceeds to the ultrasonic signal based approach. This research had been successfully done with the maximum and the minimum yield percentage between image processing and ultrasonic signal based approach method are 17.12 percent and 8.52 percent. Keywords— Image Based Approach, Ultrasonic Signal based approach, Composite Laminates, Defect Detection. I. INTRODUCTION Composite material has been used in a wide variety of engineering applications including aerospace, automobile, marine and rail industries due to its high performance such as low weight, high strength and stiffness[1]. Ye, Lu et al. [2] mention that the composite material is being use to produce aircraft components such as aileron, elevator, rudder control surface, landing gear door, fuselage side panel etc. This situation shows that the uses of composite material is being gradually increased in aerospace manufacturing industries. On top of that, Non Destructive Testing (NDT) becomes a crucial process in aerospace composite manufacturing industries where this inspection process typically closes with a high technology detection system where accuracy and quality of inspection is a top priority. The most significant defects occur during the manufacturing process are porous, and impact damage occurs during in service use caused serious damage to composites such as delamination, matrix and fibre cracking[1]. This entire defect will lead to final fracture of the material. Therefore, appropriate technique has been introduced since basic visual inspection known as “coin tap” test [3] until Non-Destructive Test technique such as ultrasonic, acoustic emission, thermography, laser Ultrasonics, X-radiography, eddy currents, shearography and low frequency methods [4]. According to Theodoros [5], ultrasonic inspection is considered as the most efficient method used for quality control and materials quality inspection to all major industries including aircraft industries. However, ultrasonic inspection technique is relatively slow in process compared to the image processing method especially in application of the large part products. In addition, this process requires competent and skilful worker due to its complicated signal analysis and setup, while image based approach which is using slightly automated process control might be conduct by a general worker with less of inspection knowledge. In this research, the results of percentage defects between image based approach which used flatbed scanner image and ultrasonic signal based approach which used single ultrasonic range finder technique are being compared and discussed in order to obtain the best solution. According to Ukida and colleagues [6], instead of the image scanner process, image based approach is an important technique for the object digital archiving, shape analysing, referencing over the network and so on. Moreover, this technique consumes less operation time compare to single ultrasonic range finder. Therefore, this technique is recommended over the single ultrasonic range finder technique especially for surface defect detection system. Furthermore, it requires less technical instruction during operation for general worker. Besides that, it also can be able to operate via online networking system where the inspection results become more reliable and also the number of inspection operator may reduce for cost effective purpose.