Effect of fiber cross section geometry on cyclic plastic behavior of continuous fiber reinforced aluminum matrix composites

Abstract

This paper investigates the cyclic plastic behavior of continuous fiber-reinforced aluminum matrix composites (CFAMCs) with different shape of fiber cross section arranged in a square packing geometry. The 2D micromechanical FEM models, composed of elastic undamaged reinforcement perfectly bonded to an elastic-perfectly plastic matrix with a volume fraction equal to 30%, are subjected to off-axis constant macro stress and a cyclic temperature history. Under such load conditions, the matrix undergoes large internal inelastic deformations potentially leading to internal crack initiation as well as macroscopic ratcheting. The computational method, the Linear Matching Method (LMM), is used throughout the analysis for the direct evaluation of shakedown, alternating plasticity and ratcheting behaviors. The effect of the matrix yield stress thermal degradation upon two common design limits, i.e., the reverse plasticity limit and the ratchet limit, is also investigated and discussed, including its influence on the off-axis low cycle fatigue crack initiation.

Cyclic Plasticity Behavior of 90° Back-to-Back Pipe Bends Under Cyclic Bending and Steady Pressure

“… Correlations of h with RPIP, RPOP, LP, and RT are shown in Eqs. (5) to (8) respectively, so that approximated shakedown boundary can be predicted without performing FEA.…”

“…The numerical procedures to calculate shakedown and ratchet limit analysis have been introduced in extensive works [8,9], therefore full numerical procedures of the LMM are not presented in this paper. Fig.…”

“…The quadratic equations are defined as Eqs. (5) to (8), respectively. For the all presented equations have the R-squared value higher than 0.98.…”

“…Iterative elastic technique is a typical approach which contains Elastic Compensation Method [4], GLOSS R-node method [5], LMM [6], and so on. The LMM has acquired distinguished reputation of providing accurate result for many complicated geometries subjected to complex loading as well as it can consider temperature dependent material parameters [7][8][9].…”

Creep-fatigue and cyclically enhanced creep mechanisms in aluminium based metal matrix composites

“…A better understanding of the micro material scale is necessary to ensure that certain types of failure mechanism do not arise, such as low cycle fatigue (LCF) crack initiation, ratchetting, cyclically enhanced creep or creep ratchetting. This involves the determination of the shakedown limit, ratchet limit, plastic strain range for LCF assessment, and creep cyclic plasticity interaction (Barbera et al, 2016b;Giugliano et al, 2017;Giugliano and Chen, 2016). The schematic representation of the stress-strain material response due to cyclic loading with creep dwell at the tensile peak, as reported in (Barbera et al, 2016b), clarifies the importance of the aforementioned design limits.…”