Dimensional measurements on workpieces made of composite materials are currently being performed after the production process, leading to high scrap rates and manpower costs. In order to increase the reliability and effectiveness of the production processes they need to be fully automated, in particular those using the filament winding technology. Progress, however, has been hindered by the lack of knowledge of appropriate metrological methods to accurately measure the size of composite workpieces during the manufacturing process.
In a first part of the project physical properties of the pre-cured and cured advanced composites will be determined that might be used for dimensional measurements of composite workpieces made of glass reinforced polyester, carbon/epoxy, kevlar/epoxy. This will include the viscoelastic creep behaviour to determine the dimensional stability of the materials under stress/strain and temperature variation; the DC electrical permittivity; the permeability; and the acoustic impedance. Measuring instruments will then be designed and constructed for in-process dimensional measurements of composite workpieces of the above range of materials; the instruments should achieve the following specification during the normal production process:
- thickness measurements in the range of 1 to 30 mm, accuracy 0.1 mm (on pre-cured and post-cured workpieces)
- length measurements in the range of 0.5 to 50 m, accuracy of 2 mm, roundness measurements in the range of 0.5 to 3 m, accuracy 1 mm (on post-cured workpieces)
The project is limited to the metrological aspects of the development of the instruments. Work directly related to the control and automation of the production process is excluded.
Funding SchemeCSC - Cost-sharing contracts
UB8 3PH Uxbridge