The objective of this project is to confer higher quality, with lower costs, to the manufacture of filament winding components, as necessary to give them a more important role in the advanced composite market.
The fundamental project's aim has been the development of a numerical simulation code able to control the Filament Winding manufacturing process.
To control the production cycle means not only to be able to input the correct parameters into the winding machine or the heating oven, but it means also to be able to predict the evolution of the manufacturing cycle as function of the input parameters as well as the final characteristics of the manufact.
In this project the main target has been reached through a theoretical modelling of the whole process and consequently its implementation into a numerical code.
The achieved results are quite good and they came up to our expectations.
There is a good relationship between theoretical and real behaviour as it is possible to see the data coming from both numerical code and real acquisition.
It is true also that not all the gauge instruments we planning would have been realised as "pellicular sensors" it has been possible to get. Anyway the data carried out by pressure sensor we used (ETRAN "EPNM-HT-200") have been quite useful to calibrate and validate that part of the numerical code evaluating the same variable.
As above mentioned, about the other variables kept under control by the gauge instruments, the real results and the theoretical ones are in good accordance with each other.
The innovative aspect of this processing strategy - with respect to the state of the art - is the possibility to optimise the whole process with regard to a manufacture which shall be axialsymmetric and shall have a figure ratio a/b between 1 and 2.5, so that 1 is less than or equal to a/b is less than or equal to 2.5.
This means to evaluate, via numerical code, the best tension of the fiber and the viscosity of the resin in the bath during the window phase, the temperature and as consequence the cure cycle; all that in order to know which will be the residual stress in the composite during and at the end of the process and which will be the final state of the manufact.
But the most important feature, which it is possible to utilise in axialsymmetric as well as in non axialsymmetric shape with a/b ratio as above mentioned, is the evaluation of the degree of cure for thermoset components.
Such a feature permits regulation in the best way of curing time and curing cycle also. Therefore it is possible to optimise the production cycle and to reduce the price of the product.
This aim will be reached through the :
-Development of a mathematical model that simulates the winding and curing processes. The model will provide the wound composite temperature, degree of cure, viscosity, fibre position and fibre tension as a function of position and time during the filament winding and subsequent curing, and the residual stresses and strains within the wound composite during and after the cure.
-Development, manufacture and setting of a sensors system able to pick up the main parameters during the winding and curing processes.
-Production of a complete software package for the solution of the mathematical model.
A subroutine of this programme code will compare the experimental process data, measured by the sensor system, with the equivalent process parameters evolution calculated by the mathematical model.
- Development of a data acquisition and experiments supervisor system (D.A.E.S.S.) that will transfer the values of the main parameters, measured by the sensor system, to the computer system.