A method for monitoring interface stress between thermocompression-cured composite parts and molds

Abstract

The present invention provides a hot-pressing cured composite material product and mould interface stress monitoring method. The monitoring method comprises the steps of: employing an interface stressmonitoring system for monitoring, wherein the system comprises a composite material support plate, a composite material product to be subjected to hot-pressing curing processing arranged on the support plate, a data collection slice arranged at the upper portion of the composite material product and a strain gage fixedly arranged at the upper surface of the data collection slice, the thickness ofthe data collection slice is below 0.4mm, the perimeter dimensions and the size of the data collection slice are the same as the perimeter dimensions and the size of the composite material product, or the difference of the perimeter dimensions and the size of the data collection slice and the perimeter dimensions and the size of the composite material product is not larger than + / -0.5mm; and after strain data is detected by employing the system, multiplying the strain data by elastic modulus data of materials required by the data collection slice to obtain interface stress of the composite material product and the mould. The hot-pressing cured composite material product and mould interface stress monitoring method can calculate the interface shear stress according to the elastic modulus of the mould materials and the measured strain, and has operability.

Description

Technical field [0001] The present invention relates to the field of hot press-solid preparation composite materials, and more particularly to a thermocomposite article and a mold interface stress online monitoring method during preparation of hot press curing composites. Background technique [0002] The resin group composite is widely used in its excellent performance in the fields of aerospace, automotive ships. The hot press canmade process (hot press curing preparation) is widely used in the molding of the resin matrix composite. However, the composite material is deformable after demolding, affecting its molding accuracy, which affects the modification of the production, is generally divided into: uneven curing shrinkage, the coefficient difference between the coefficient of thermal expansion of the resin and carbon fibers and the interaction of the mold and the parts. Residual stress results in deformation of the article, in which the last factor is particularly worthy of ...

AI Technical Summary

Problems solved by technology

[0004] 2) The stress state at the groove on the mold may be different from other places, so this method may affect the authenticity of the interface stress test;

[0005] 3) For certain materials, it is more difficult to groove the mold, and the operation is more difficult. For example, the mold is made of resin-based composite material. It is difficult to remove the fibers in the groove when processing small grooves according to this method, which will further affect the interface stress test. authenticity;

[0006] 4) If the optical fiber is used as the sensor in this method, the bending will occur when the optical fiber is led out of the groove, which will have a huge impact on the measurement

[0007] Therefore, the above method has the problem of whether the measured data can truly reflect the interface stress between the mold and the composite material part, and the method has poor operability

Images