Numerical Modeling of the Mechanical Response of a Continuous Fiber Ceramic Composite in Flexure

Finite element analysis model of the cumulative damage failure process in a continuous-fibre ceramic composite loaded in flexure

“…Sensitivity analyses [18] indicated that the applied force versus load point displacement curve for the FEA model is more sensitive to bre properties than to those of the matrix. This is mainly because the ultimate strength of the bre controls the composite strength when these elements have been 'killed', correlating to the peak force and non-linear unloading region of the curve.…”

“…However, a model based on probabilistic strength distribution has also been successfully implemented where normally distributed strengths using the statistics shown in Table 1 were assigned to the matrix and bre elements [18].…”

“…Physically, the matrix has been saturated with cracks and bre failure has begun in earnest since the matrix has 'shed' the majority of internal force to the bres. In the FEA model the peak force was particularly sensitive to the choice of the in situ bre strength [18]. Fibres in the pristine condition generally have welldescribed, statistically distributed strengths.…”

“…Physically, most of the matrix and bres in the tensile region have failed. Differences between the FEA model and experimental results have been attributed to the assumptions of the model regarding physical aspects of the test [18]. For example, friction and rough surfaces at the contact points were not incorporated in the FEA model whereas, experimentally, large de ections of the exure test specimen may cause it to wedge between the support points.…”

“…Next, as shown in Fig. 3a, two coincident sets (for the matrix and bre meshes) of eight-noded quadrilateral elements were used to de ne the body of the bend beam [18]. A mesh size of 1760 elements (see Fig.…”