Structural model of heterogeneous material (microsphere foam) straining and failure under hydrostatic loading

Abstract

Object and purpose of research. The paper investigates polymeric composite material of syntactic foams type being by nature a heterogeneous medium and consisting of polymeric matrix, filled with spherical inclusions: microspheres. The main purpose of this this paper is to develop a structural model of straining and failure for this type of materials under hydrostatic pressure and software and mathematical apparatus for model implementation. Materials and methods. The input data for this research were composition and structure of syntactic foam material as well as the performance of its components (polymeric matrix and glass microspheres). Structural model was developed on the basis of solutions to linear elasticity theory problems using Lubachevsky – Stillinger algorithm for the formation of structure, homonization methods, etc. A calculation algorithm implemented in code in the С++ language was developed on the basis of the designed mathematical apparatus. Verification of calculation results was carried out by comparison with failure test results of samples of one of the grades of syntactic foam under short-term hydrostatic pressure loading. Main results. Structural model of syntactic foam type material straining and failure under hydrostatic pressure was developed. A calculation algorithm implemented in program code written in the С++ language which is relatively highly efficient for analysis of real structures with a large number of microspheres of the order of 105. Correlation with experimental results showed compatibility of modelling results in terms of both quantitative and qualitative estimates. Conclusion. The developed structural model allows with a high degree of confidence to describe the processes of damage and failure accumulation in syntactic foam under hydrostatic pressure. For practical purposes the model can be used applied for prediction of syntactic foam performance (strength, bulk strain and buoyancy), based on the properties of the initial components – microspheres and polymeric matrix.