Dynamic And Perspective Measurement Of Composite Material's Internal Temperature-the Theory Introduction Of Three-dimensional Strain Field Distribution

Composite material is a new material which is composed of two kinds of substances with different properties through chemical or physical method. The interior and various substances of composite material, by adopting one's strong points while overcoming other's weakness, make it become excellent in combination property and can be applied to complex and harsh environment. The mechanical property of material is the mechanical characteristic which is reflected under a variety of external load like tension, compression, bending, torsion and so on in different temperature, medium or humidity circumstance. The paper, based on a variety of measurement techniques, has improved optical interference spectral domain phase contrast B scanning algorithm and overcome the enormous measurement difficulty caused by material's refractive index changing with temperature.The paper would introduce the monolithic construction of optical interference spectral domain phase control B scanning system especially introduce the selection and design of Michelson interferometer's main components such as light path structure, light source and spectrograph in details which provide hardware foundation for measurement experiments.The emphases of the paper are the theory of optical interference spectral domain phase control B scanning algorithm, light intensity formula, phase difference formula, M reflection surface interference formula in time domain and frequency domain, K space's intensity and frequency domain formula, the formula of the surface displacement field and the strain field under force, the formula derivation of the surface displacement field and the strain field under the heating extruding deformation and the demonstration of the temperature strain field measurement's feasibility on theory. The paper would carry out temperature-strain field experiment and temperature-displacement field experiment respectively for epoxy resin matrix composite material and silicone rubber material.In the paper, the measurement depth of phase contrast B scanning system is 5.98mm and the depth measurement resolution is 15?m.Combined with optical interferencespectral domain phase control B scanning system, it is concluded from the experimental results that the displacement field and strain field of composite material are consistent with the theoretical analyses. Through the analysis and demonstration of the experimental results, it can be seen that optical interference spectral domain phase contrast B scanning algorithm has the following advantages.Firstly, high measurement speed. The high measurement speed can make the chromatography measurement of the deformation field inside the material come true which only needs a shoot for the interference spectrum. Secondly, high measurement sensitivity. It can achieve 10nm measurement accuracy. Thirdly, strong anti-noise ability. The material is combined with the phase unwrapping method which could operate efficiently and anti-noise strongly. Experiments show that the method can real-time and accurate measure the transparent or translucent composite material's internal strain field distribution which can be used in material's solid and hot deformation as well as internal micro defect's detection. It is also expected to be applied in equipment mechanical coating, the thin film detection of composite material of the micro electrical-mechanical system (MEMS) and many other research fields which need high precision continuous deformation. Therefore it is an effective technical method to study the internal mechanical properties of composite material.