In reinforced materials, various theoretical studies are based on the shear-lag theory. In recent years, extensive investigations have been conducted to predict the steady state creep behaviors of the materials (see Figure 1). Therefore, a thorough knowledge of creep characteristics and deformation mechanisms of reinforced and nonreinforced materials is required to utilize these composites in high stress and high temperature applications. Creep phenomenon may be happened in short fiber composites or nanocomposites because of any elevated temperatures and applied loads which can be dangerous for composites and structures. Consequently, a logical analysis of the creep behavior and its mechanisms for these materials is crucial. Additionally, predicting the creep behavior is very important for designing the advanced reinforced/nonreinforced materials. For instance, spaceships, turbine blades and discs are commonly under the creep effects.
Therefore, study on the process of the creep phenomena is essential and significant for engineering applications concerning high temperature and high stress. On the other hand, creep phenomenon in solids under high stress and temperature is one of the important topics in the scientific societies, and therefore, the creep analysis become more significant in various industries. Creep is a slow, continuous deformation of a material under constant stress and temperature.