Automatic Fiber Placement ( AFP ) Technology , Actual State and Future Improvement through Using NDT ( Ultrasonic ) Equipment in On-line Processing Prof . PhD
In this paper are presented all of the technologies used for research at the Institute for Advanced Composites and Robotics (IACR). Focus is put on the automated fiber placement (AFP) technology and the equipment used to perform this technology. Analysis presented, refer to possible mistakes in the final product, composite part intended to be a primary structure of an airplane, due to the inability to know the influence of the compacting roller, or the characteristics of the prepreg on the occurrence of micro voids in the laminate of the part produced. As a response to this acknowledgement, preliminary research is done at IACR where ultrasonic sensor is used for nondestructive testing (NDT) in composite materials. This preliminary research has shown that it should be further inspected whether ultrasonic sensor following the compacting roller, could improve the impacting process and diminish the number of voids in the final product.
Endoscopic Shearography and Thermography Methods for Nondestructive Evaluation of Lined Pressure Vessels
The goal of this research effort was the development of methods for shearography and thermography inspection of coatings, bonds, or laminates inside rocket fuel or oxidizer tanks, fuel lines, and other closed structures. The endoscopic methods allow imaging and inspection inside cavities which are traditionally inaccessible with shearography or thermography cameras. The techniques are demonstrated and suggestions for practical application are made in this report. Drawings of the experimental setups, detailed procedures, and experimental data are included.
Control of reflective cracking
The first is 'fatigue' cracking of the layer. This type of cracking is the result of the application of loads on the pavement and is controlled by appropriate thickness design which 'ill not be discussed in detail here. Thickness design includes not only the design strength and thickness of the stabilised, but other design elements such as delaying reflection cracking, or limiting stresses in the stabilised layer, by adopting a minimum thickness of overlying material. This may include an unbound layer utilising the 'upside down' pavement approach. The actual thickness required of the overlying material varies but for example PIARC (Ref.1) recently reported when the thickness of coated materials exceeds 20 cm the emergence of shrinkage cracks at the surface is generally uncommon; when it is 15 cm thick, the cracks emerge at the surface, but do not shorten the life of the surface course, especially if they are sealed. This experience has been gained 'with legal axle loads of 130 kN, considerably greater than the Australian legal axle load.