Strain properties of particulate composites with microcracks

Journal Article · Tue Mar 01 04:00:00 EST 1994 · International Applied Mechanics

OSTI ID:114682

Shikula, E N ^[1]

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1. Institute of Mechanics, Kiev (Ukraine)

Many composite materials deform nonlinearly when subjected to sufficiently heavy loads. Both the nonlinearity of the strains of the components of the composite and the microcracks which form in them during loading make the relationship between the macroscopic stresses and strains nonlinear. The group of materials which undergoes microscopic fracture during loading includes composites with brittle components - polymer composites used at low temperatures, composites with a carbon binder, and ceramic composites. The microfracture of composite undergoes such fracture. No fractures are present in the component up to a certain value of stress intensity. Microcracks, modeled by pores, are formed upon attainment of the critical load in the component. The volume content of pores increases in accordance with a certain specified law as stress intensity increases in the component, and any increase in pore content is accompanied by further stress redistribution in the components. Such stress redistribution in turn affects microcrack formation and growth in the composite. Since the moduli of the components depend on their porosity and since the increase in the number of pores due to microcracks depends on the load, then ultimately the effective moduli of the composite will depend on the macroscopic stresses, i.e. the effective deformation of the composite will be of a physically nonlinear character. This makes it possible to generalize the determination of effective elastic constants for a porous composite to the case of nonlinear strains. Here, we propose an algorithm for calculating the nonlinear strain properties of particulate composites with porous components in the case of their microscopic fracture.

• OSTI ID: 114682
• Journal Information: International Applied Mechanics, Journal Name: International Applied Mechanics Journal Issue: 9 Vol. 29; ISSN IAMEEU; ISSN 1063-7095
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
CRACK PROPAGATION
CRACKS
MATHEMATICAL MODELS
STRAINS