Computational Modeling of Beam Network

At sub-micron level, we used Abaqus and Matlab to model a collection of collagens as a beam network model. The objective was to investigate the effects of fiber orientation, void volume fraction and window size on the constitutive response of a randomly generated beam network. The effect of dangling fibers on the fiber volume fraction and constitutive response was discussed as well. A FORTRAN program was used to generate the random fiber network. A specially written Matlab^® script was then used to preprocess the data and was inputted into Abaqus^® for analysis. The result showed that generally C₁₁₁₁ value decreased with increasing window size, higher scattering angle, and higher void volume fraction. In addition, generally there was less scattering for higher window size, higher scattering angle and higher void volume fraction. Besides, three cases of estimating volume fraction for a beam network were proposed. The result showed that the volume fraction usually used in other research papers might be overestimated due to dangling fibers, resulting in inaccurate constitutive response. The outputs from those two scales are then compared with the nanoindentation results and other theoretical models.