Fracture parameters formulation for single edge notched AS4 stitched warp-knit fabric composite plate

The three-dimensional problem of the fracture for the single edge notched tension plate (SENT) of orthotropic material is considered in this paper. The finite element solution is used to evaluate the singular and non-singular terms of the William series, i.e. Stress intensity factor (SIF) and T-stresses namely T11, T13 and T33. Based on the obtained numerical results, a fitting procedure is performed in order to propose analytical formulations giving the fracture parameters near the crack tip. The obtained results are in good agreement with the finite elements calculation and other literature results

Fracture parameters formulation for single edge notched AS4 stitched warp-knit fabric composite plate

The three-dimensional problem of the fracture for the single edge notched tension plate (SENT) of orthotropic material is considered in this paper. The finite element solution is used to evaluate the singular and non-singular terms of the William series, i.e. Stress intensity factor (SIF) and T-stresses namely T11, T13 and T33. Based on the obtained numerical results, a fitting procedure is performed in order to propose analytical formulations giving the fracture parameters near the crack tip. The obtained results are in good agreement with the finite elements calculation and other literature results

Fracture parameters formulation for single edge notched AS4 stitched warp-knit fabric composite plate

The three-dimensional problem of the fracture for the single edge notched tension plate (SENT) of orthotropic material is considered in this paper. The finite element solution is used to evaluate the singular and non-singular terms of the William series, i.e. Stress intensity factor (SIF) and T-stresses namely T11, T13 and T33. Based on the obtained numerical results, a fitting procedure is performed in order to propose analytical formulations giving the fracture parameters near the crack tip. The obtained results are in good agreement with the finite elements calculation and other literature results

Fracture parameters formulation for single edge notched AS4 stitched warp-knit fabric composite plate

The three-dimensional problem of the fracture for the single edge notched tension plate (SENT) of orthotropic material is considered in this paper. The finite element solution is used to evaluate the singular and non-singular terms of the William series, i.e. Stress intensity factor (SIF) and T-stresses namely T11, T13 and T33. Based on the obtained numerical results, a fitting procedure is performed in order to propose analytical formulations giving the fracture parameters near the crack tip. The obtained results are in good agreement with the finite elements calculation and other literature results

Fuzzy Analytical Hierarchy Processes for Damage State Assessment of Arch Masonry Bridge

The present work proposes a fuzzy analytical hierarchy approach for decision making in the maintenance programming of masonry arch bridges. As a practical case, we propose to classify the degradation state of the Mohammadia masonry bridge. A large number of criteria and sub-criteria are combined to classify this type of bridges through visual inspections. The main criteria (level 1) considered in this work are the history of the bridge, the environmental conditions, the structural capacity and the professional involvement of the bridge. In addition, these criteria are subdivided into several sub-criteria (level 2) which are, in turn, subdivided into sub-criteria (level 3). Considering these criteria and sub-criteria, weights Wiare calculated by fuzzy geometric mean method of Buckley. Subsequently, expert scores were assigned to calculate the overall score CS reflecting the degradation of the considered infrastructure. Thereafter, the masonry arch bridges are classified respecting the French IQOA scoring system using the overall scores value CS. The proposed classification method gave similar results provided by an expert’s study realized previously as part of a national patrimony preservation policy. The obtained results are in good agreement, which makes this method an effective scientific tool for decision-making in view of prioritization of the maintenance after systematic inspection of masonry bridges such as the bridge studied in this work. Doi: 10.28991/cej-2021-03091770 Full Text: PD

Numerical Analysis of Plate Thickness Effect on Residual Stress Distribution around a Cold Expanded Hole

The process of cold expansion creates compressive stresses around the mounting hole, which can help to reduce stress concentrations during the loading of a structure. A numerical simulation using the finite element method was conducted to analyse the effect of cold expansion on perforated plates of different thicknesses. The simulation considered the thickness of the plate and the tapered mandrel and examined the induced residual stresses. The results showed that the magnitude of the circumferential residual stresses varied depending on the thickness of the plate and that the extent of the zone of compressive stresses was strongly affected by the plate thickness. These findings are particularly relevant to the optimisation of the cold expansion process, as the optimal parameters for a particular plate thickness may not be optimal for some other thickness. Therefore, the results of this study can guide the optimisation of the cold expansion process for different plate thicknesses

Finite element based fatigue analysis of 6082 Aluminum alloy under random loading

Mechanical and structural components are subject in the most cases during their services to random loading. For this reason, it is necessary to reduce the complex history of these kinds of loading in a series of constant amplitude cycles. There are several counting methods that lead to different results. Among all these methods, it is recognized that the Rainflow Cycle Counting method provides the most conservative results. In this paper, a finite elements analysis technique is presented to predict the fatigue life using this method associate with the S-N method which is used for high cycle fatigue applications that makes no distinction between initiation or growing a crack, but rather, predicts the total life to failure. Comparison between numerical and experimental results is considering in this paper.

Finite element based fatigue analysis of 6082 Aluminum alloy under random loading

Mechanical and structural components are subject in the most cases during their services to random loading. For this reason, it is necessary to reduce the complex history of these kinds of loading in a series of constant amplitude cycles. There are several counting methods that lead to different results. Among all these methods, it is recognized that the Rainflow Cycle Counting method provides the most conservative results. In this paper, a finite elements analysis technique is presented to predict the fatigue life using this method associate with the S-N method which is used for high cycle fatigue applications that makes no distinction between initiation or growing a crack, but rather, predicts the total life to failure. Comparison between numerical and experimental results is considering in this paper.

Numerical Analysis and Optimization of the Residual Stresses Distribution Induced by Cold Expansion Technique

Abstract. This paper presents a numerical investigation about the influence of mandrel shape on residual stresses induced by the cold expansion procedure. Thus, ball and tapered pin are used for cold expanding the plate. As, the entrance face presents the lowest residual stresses throughout the hole thickness, we propose to solve this problem by varying the mandrel taper degree, instead of applying a double expansion.  The obtained results show that the tapered pin is more suitable for the cold expansion. More, low taper increases the residual stresses at the entrance, reaching the values generated at the exit face

Finite element modeling and analytical solution of a semi-elliptic crack's Jintegral

In this work, we first evaluate the J-integral rupture parameter as a function of various crack parameters (crack size, rod dimensions, intensity and nature of loads) for various crack form. In a second step, and in the base of the results obtained by the finite element method, we propose formulas of the factor shape, whose implementation remains rather simple and inexpensive in terms of time, effort and means to the engineer in order to predict evolution of the rupture behavior of a cylindrical component with a semielliptical crack emerging from the surface. The comparison of the proposed analytical solution showed a good performance relatively with results of the literature