A theoretical analysis of the strength of composite gels with rigid filler particles

Abstract

The strength, under uniaxial load, of composite gels containing filler particles has been investigated by calculating the stress concentration in the gel matrix. The particles were assumed to be rigid spheres, and the interaction between the particles was taken into account based on a self-consistent model. The bonding between the particles and matrix was treated for two typical cases, (1) perfectly bonded, (2) smoothly connected. For case 1, the analytical result shows that the stress concentration factors decrease with the increasing of the volume fraction of filler. For case 2, the stress concentration factors are independent of the volume fraction of filler. The structural failure caused by the stress concentration was analyzed.

Influence of particle size and interfacial interactions on the physical and mechanical properties of particle-filled myofibrillar protein gels

“…A number of theoretical approaches have been proposed to describe the effect of the volume fraction ller (f f ) on the small deformation properties of particle-lled composite systems (see cited material and references therein). 2,8,[33][34][35] Several of these models which were originally proposed to describe the behavior of the shear storage modulus of such composites can also be adapted to describe the effects of f f on the Young's modulus. One such model was that originally derived by van der Poel, 36 with subsequent modications by Smith.…”

“…15 This will result in local stress concentrations near the ller/matrix interface, which may exceed either the interfacial bonds or the bonds supporting the gel structure, leading to the nucleation of fractures. 31,34,51 In contrast, the smaller particles allow for a more homogeneous distribution of ller mass, greatly increasing the extent of ller/ matrix interactions, and causing less interfacial stress. Therefore, the extensive particle/ller interactions of the smaller RBX llers, coupled with the strong interfacial adhesion result in an elevated s 50 while maintaining structural integrity to a greater extent.…”

Food-grade filler particles as an alternative method to modify the texture and stability of myofibrillar gels

“…The incorporation of rigid particles in a flexible matrix can contribute to stress concentration at the particle-matrix interface during deformation, which has been shown to act as a nucleation point for microfractures 29 . Such debonding from the matrix during deformation has also been shown in particle-filled food gels in which the modulus of the filler and matrix are comparable.…”

“…Although the Resilience of the composites containing the crystalline fillers gradually decreased with increasing m f , the decreased rigidity of the partially hydrated starch granules, as well as their compatibility with the protein network, resulted in an overall neutral impact. Although it was previously noted that the presence of rigid particles may lead to stress concentration at the interface 29 , the partial swelling of the granules could be expected to provide some flexibility to the filler, thus diminishing the stress concentration effect and decreasing the occurrence of microfractures at the filler/matrix interface.…”

Dynamic experimentation on the confocal laser scanning microscope: application to soft‐solid, composite food materials

“…Mixed protein/polysaccharide gels often exhibit phase‐separation which is ‘emulsion‐like’ in nature, with spherical inclusions present within a continuous matrix (Morris, 1985). Although the large deformation and failure behaviour of these materials is poorly characterized, assessment of the mechanical response of analogous composite gels has been conducted, both experimentally and theoretically (Brownsey et al ., 1987; Gao & Lelievre, 1994). When a weak interfacial bond occurs between the two phases, debonding can be anticipated if the included particles have significantly higher elastic modulus than the continuous matrix.…”