Experimental Evaluation of the Formation and Evolution of Acrylic Polymer Composite

Acrylic polymer composite, also known as “bone cement,” is widely used in orthopedic surgery to anchor hip arthroplasty. The distribution of the random damage over the various modes changes as the stress increases, and it occurs in the form of microscopic events with specific characteristics. Evidence of the random damage is the continuous occurrence of randomly generated microscopic damage events as observed by many authors. Knowledge is lacking, however, the quantification of these random damage events. The occurrence of random damage events followed primarily a Gaussian probability distribution model, $$ f(y)={a}_0{e}^{-{\left(\frac{y-{b}_0}{c_0}\right)}^2} $$ for the cases under tension loads, where ao, bo, and co are the magnification factor (the highest probability when the scale of an event is equal to bo), and bo and co are related to the centroid, and peak distribution. An exponential distribution model $$ f(y)={a}_0{e}^{-{b}_0y} $$ was found for the cases under bending, where ao is, again, the magnification factor, and bo is the damage event scale constant. We found a fact that the occurrence of random damage events was relatively independent of the applied stress in certain loading stages such that there were not significant changes of random damage events when the applied stress increased. This fact suggested that the use of damage event accumulation may be a better indicator to reveal the integrity of this material than that of the applied stress alone. Our empirical models may be used as a ground work to reveal and describe the occurrence of multiscale random damage events in brittle and semi-brittle materials.