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Two pot experiments were conducted to study the effects of intercropping with cadmium (Cd) accumulator plant Eclipta prostrata and hyperaccumulator plant Crassocephalum crepidioides on the growth and Cd accumulation of tomato seedlings. In the preliminary experiment, intercropping with E. prostrata and C. crepidioides promoted the growth and decreased the Cd content in roots and shoots of tomato seedlings. In the further experiment, intercropping with E. prostrata and C. crepidioides had the same effects on the growth and Cd content of tomato seedlings as the preliminary experiment. In the further experiment, when three plant species (E. prostrate, C. crepidioides and tomato) intercropping together, the root and shoot biomasses of tomato seedlings got the maximum, and the Cd content in tomato seedlings got the minimum. Compared with the monoculture of tomato, three plant species intercropping increased the root and shoot biomasses of tomato seedlings by 49.28% and 64.19%, respectively, and decreased the Cd contents in roots and shoots of tomato seedlings by 17.35% and 22.35%, respectively. Intercropping with E. prostrata and C. crepidioides also increased the photosynthetic pigment content and enhanced the antioxidant enzyme activity of tomato seedlings. For accumulator and hyperaccumulator plants, intercropping with tomato inhibited the growth of E. prostrata and C. crepidioides, while increased the Cd content in two plant species. Therefore, intercropping with E. prostrata and C. crepidioides could promote the growth and reduce the Cd uptake of tomato seedlings, and three plant species intercropping together was the best combination. [ABSTRACT FROM AUTHOR]

This paper investigated the role of longitudinal reverse bending stress on the initiation of reverse transverse defects. The longitudinal reverse bending stress occurs due to the reverse bending of the rail between two-wheel passage leading to the generation of tensile bending stress at the railhead and the lower head areas. The longitudinal bending stress was investigated as part of a parametric study on the rail cant angle, rail stiffness, lateral-to-vertical load ratio, and rail profile. A finite element model was created by using ABAQUS to analyze the extent of reverse bending in rails with respect to the chosen set of parameters. Under different lateral-to-vertical load ratios of 0, 0.3, 0.5, and 0.7, the maximum stress at the rail lower gauge corner was found to vary between 14.57MPa and 15.47MPa under the reverse bending condition. Similarly, low values of tensile stress under the reverse bending scenario were observed with changes in the rail cant angle and axle spacing with respect to different coal and iron ore wagons. The results revealed that the magnitude of the bending stress under different conditions of reverse bending was not significant enough to initiate a crack at the lower gauge corner. [ABSTRACT FROM AUTHOR]

This paper is aimed at incorporating all possible micro-scale damage mechanisms, namely, fiber failure, matrix cracking, fiber-matrix debonding and delamination in multi-fiber multi-layer representative volume element (M2RVE) subjected to multi-axial loading. Different loading conditions have been selected to induce a particular or combined damage mechanism/s to study the damage evolution. The predicted constitutive material responses for tensile and in-plane shear loading by M2RVE are in reasonably good agreement with the experimental results. M2RVE then used for capturing all the microscale damage mechanisms even for complex multi-axial loading. The stress–strain responses have been effectively captured for different combinations of dominant damage mechanisms. [ABSTRACT FROM AUTHOR]

A shear-lag model with a cohesive fibre–matrix interface has been developed for the analysis of stress transfer between the fibre and the matrix in fibre-reinforced composites in this paper. A bilinear cohesive damage evolution law is used to describe the fibre–matrix interface behaviour. The governing equations for the interfacial shear stress and the axial stress in the fibre are derived. Accurate analytical solutions are obtained when the fibre–matrix interface is in the initial linear elastic deformation regime. When debonding occurs, interfacial damage and softening are modelled by superposing two elastic stress systems and satisfying the damage evolution law at both ends of the damage process zone, and approximate analytical solutions are obtained. The stress distribution and evolution during the fibre pull-out, the maximum pull-out force and the pull-out curve have been analysed using a shear strength-based debonding criterion. Analytical expressions for the maximum fibre pull-out force and its limit as the embedded fibre length approaches infinity are obtained. In addition, the new function proposed for describing the radial distribution of the shear stress in the matrix fixes the problem of zero shear-lag parameter when b / a approaches infinity, enabling the shear-lag analysis to deal with low fibre volume fractions. Generally, the analytical solutions compare satisfactorily well to the cohesive finite element calculations and experimental data in the literature. [ABSTRACT FROM AUTHOR]