Porosity is a result of a deficiency in the production process that could lead into the mechanical degradation of CFRP composite structures. Therefore, some checkpoints for determining its presence during part manufacturing have to be established, verifying that precise threshold values are not exceeded. Currently, porosity characterization is carried out by an indirect way using ultrasonic tec...

Additive manufacturing (AM) technologies have been successfully applied in various applications. Fused deposition modeling (FDM), one of popular AM techniques, is most widely used method for manufacturing of plastic materials. Due to the poor strength properties of pure plastic materials, there is a critical need to improve mechanical properties for FDMfabricated pure plastic parts. One of the ...

This paper describes a research program that was conducted in two phases to study the behavior of a high modulus CFRP system for strengthening steel structures. The first phase of the research consisted of an experimental program and finite element analysis to study the bond characteristics of the system. The findings indicate that a reverse tapered plate end detail can effectively increase the...

This work presents an optical non-contact technique to evaluate the fatigue damage state of CFRP structures measuring the irregularity factor of the surface. This factor includes information about surface topology and can be measured easily on field, by techniques such as optical perfilometers. The surface irregularity factor has been correlated with stiffness degradation, which is a well-accep...

─This paper presents the retrofitting of beam-column joint using CFRP (Carbon Fiber Reinforced Polymer) and steel plate. This specimen was tested until failure up to 1.0% drift. This joint suffered severe damages and diagonal cracks at upper crack at upper column before retrofitted. CFRP were wrapped at corbel, bottom and top of the column. Steel plates with bonding were attached to the two bea...

At the moment the huge majority of the structural parts is based on pre-preg designs and standard prepreg manufacturing technology. They are processed conventionally out of Hand Lay-up and cured in autoclaves. The cost drivers are the hand-work, the use of autoclave and the quality control. The future success of new helicopter programs is strongly dependant on the development of cost efficient ...

An automobile industry have an interest in replacement of conventional leaf spring with composite leaf spring to get better performance with less weight. This paper deals with by replacing the conventional leaf spring with composite leaf spring. The dimensions of an existing conventional steel leaf spring of a light commercial vehicle were taken to fabricate the special die which is further use...

This paper presents a data fusion method between the results of ultrasound using phased array at 5MHz frequency and those obtained through eddy current examination at 1-10MH frequency. The obtained results are compared with destructive tests, a very good correlation being obtained. The effects of delamination over the properties of CFRP are studied using dynamic mechanical analyzer, emphasizing...

Carbon fiber reinforced polymers are playing a key role for future aircraft structure design concepts as the newest technical developments for aircraft models B787 and A350 are showing. Due to the specific mechanical properties of this composite material and the novel manufacturing and machining techniques for large-scale CFRP made aircraft structures, it is necessary to establish an adequate p...