Objetivo Development of the utilisation of tubular equipment made of composite materials is presently faced with the lack of quality guaranteed by the equipment that is implemented. This is of importance in the case of vertical tubings, which are at the same time very heavy mechanically and for which intervention cost is the highest.Therefore, the object of this programme is to create, adapt or finalize non-destructive control methods based on different physical phenomena (acoustic, thermal, electrical,etc) so to ensure the reproducibility of the produced equipment.However, the non-homogeneous nature of these materials, implies in practice, that the adaption of operational methods be done in direct with the usage value of the equipment, in this case the loss of tightness of the pipes and of the ancillary equipment. Hence, this programme is followed by a study on the incidence of faults on the utilisation properties of the tubings.Reproducibility of faults related to the manufacturing process of composite material pipes (for instance porosity) was not possible. Thus, it is not envisaged to pursue works along this orientation as it is not possible to evaluate the incidence of these faults on the behaviour of pipes during service. On the other hand, reproducibility and characterization of defects related to shocks was possible thanks to the use of appropriate machines using the weight dropping principle. Furthermore, a simple non-destructif control method based on the principle of luminous transmission has proven a good aptitude to detect these faults. Furthermore, tests benches were manufactured to determine in a realistic manner the ageing of composite material tubings. A number of commercial supplies was tested at 90 C at internal pressure with or without superposed axial traction, allowing to define the limit solicitations to be respected so to obtain satisfactory behaviour of these products during service. However, this experimental method presents the disadvantage of a very long and costly implementation. Also, the dispersion of experimental results, phenomenon inherent to the method and the material, would not facilitate in the future, a comparative study of the behaviour of good pipes and faulty pipes so evidence the incidence of faults on the behaviour of these pipes during service. These results do not impell to pursue works beyond the feasibility study phase. Nonetheless, it is possible to envisage favourably the development of several punctual actions which could be performed independently to this project.Non-destructive control methods for composite materials have been developed particularly for the aeronautical domain, and concern top quality materials, most often based on carbon fibers. In the case of more industrial epoxy-glass fiber tubings, the detection of faults and the estimate of their critical point must be evaluated simultaneously.Furthermore, the diversity of existing equipment and methods imply a number of choices possible for each type of development, as well as the performance evaluation of reference equipment. The programme has been divided in two main phases:a) FeasibilityIn this preliminary phase, two different studies will be carried out.- evaluation of real performances in time of tubings selected as test elements. This evaluation will be carried out under internal pressure, with and without axial traction, in the presence of water and under temperature. This evaluation will also include an analysis of their creeping properties.- the inventory and evaluation of the performances of possible methods of non-destructive control, in relation with faults currently observed and with their possibility of being used at the factory or on worksites. This task can be carried out without problem in laboratory test tubes.This phase will end with the precise definition of applicable methods and their utilisation range. Obviously, only a small number of methods will be chosen for the following phase. Also most of the faults encountered will depend on them. Hence, this phase is an ending point for which a reorientation of the programme could be envisaged.b) Development of specific methodsThis phase will be entirely carried out on tubular elements, as similar as possible with industrial tubings. It will include the following tasks:- Creation of tubings with calibrated artificial faults similar to those encountered previously- Evaluation of the limit performances of chosen control methods ( size, number, etc)- Evaluation of the incidence of these faults on the lifespan of tubings. This incidence will be measured by long duration tests, under static and eventually under fatigue conditions. Considering the special feature of the mechanical operating mode of the tubings, this evaluation will not only be carried out under internal pressure, but also under traction, and anyhow under temperature.Attempt will also be made, when possible, to follow the progress of faults observed initially by the chosen control methods.Thus, it will be possible, at the end of this phase, to define a coherent control scheme for the tubular elements made of composite materials, which will include the maximum size of the admissible fault and the minimum performances of the control methods to be implemented for an appropriate detection. Programa(s) ENG-HYDROCARB 2C - Programme (EEC) of support for technological development in the hydrocarbons sector, 1986-1989 Tema(s) 1.6 - MISCELLANEOUS Convocatoria de propuestas Data not available Régimen de financiación DEM - Demonstration contracts Coordinador GERTH Aportación de la UE Sin datos Dirección 232 AV. NAPOLEON BONAPARTE 92500 Rueil Malmaison Francia Ver en el mapa Coste total Sin datos
