Delamination threshold load for dynamic impact on plates

Abstract. This paper investigates the influence of wheel defects on the development of rail defects up to a state where rail prompt replacement becomes necessary taking into account different models of the dynamic contact between a wheel and a rail. In particular, the quasistatic Hertz model, the linear elastic model and the elastoplastic Aleksandrov-Kadomtsev model. Based on the model of the wheel-rail contact the maximum stresses are determined which take place in the rail in the presence of wheel defects (e.g. flat spot, weld-on deposit, etc.). In this paper, the solution of the inverse problem is presented, i.e., investigation of the influence of the strength of a wheel impact upon rails on wheel defects as well as evaluation of the stresses emerging in rails. During the motion of a railway vehicle, the wheel pair position in relation to rails changes significantly, which causes various combinations of wheel-rail contact areas. Even provided the constant axial load, the normal stresses will substantially change due to the differences in the radii of curvature of contact surfaces of these areas, as well as movement velocities of railway vehicles.

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“…5) The model where the force of interaction is divided into loading and unloading steps [11,12]. For a loading step -(1), for an unloading step -…”

Section: Contact Problemmentioning

confidence: 99%

“…In these cases [3,5,7,9,11,12,13] the maximum impact force of a wheel with a flat spot on rail is determined as:…”

Section: The Determination Of the Stresses In The Interaction Of Wheementioning

confidence: 99%

Modeling the dynamic behavior of railway track taking into account the occurrence of defects in the system wheel-rail

et al. 2017

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“…Wisnom et al [13] numerically evaluated discrete transverse cracks in polymer composites by means of cohesive zone interface elements. Through combining stress-based and fracture mechanics approaches, they could accurately predict initiation and propagation of different damage modes.…”

Section: Introductionmentioning

confidence: 99%

Experimental–numerical study on minimizing impact induced damage in laminated composites under low-velocity impact

Pashmforoush

Fotouhi

Sarhan

2017

Journal of Reinforced Plastics and Composites

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In this study, an experimentally validated numerical analysis was performed toward optimization of stacking sequence in multidirectional laminated composites subjected to low velocity impact. For this purpose, an optimization program was developed by integrating Finite Element Method (FEM) and Multi Objective Genetic Algorithm (MOGA) using modeFRONTIER. In this regard, three objective functions were defined; one, based on Hashin failure theory and two others based on interlaminar shear and tensile stresses. These objective functions were aimed to be optimized through tailoring ply angles with special focus on minimizing impact induced damage. The obtained results indicated that the proposed optimization method is an effective tool for optimizing stacking sequence of laminated fiber reinforced composite materials.

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“…impact damage resistance must be at hand. A number of impact damage resistance models and modelling techniques are available for solid impact bodies [1][2][3][4]. The applicability of these models for analysis of ice and stone impact is not fully assessed.…”

Section: Introductionmentioning

confidence: 99%

“…Kim and co-workers [5,6] have addressed the ice impact event and developed a semi-empirical approach to the problem. These types of simple and easily accessible engineering models [1][2][3][4][5][6] are required in the design phase as a complement to the more detailed and cumbersome analyses using numerical approaches. The most promising numerical procedures employ soft particle hydrodynamics (SPH) to model the behaviour of the ice at impact [7].…”

Section: Introductionmentioning

confidence: 99%