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Finite element analysis of three-dimensional periodic notched plates
No full textUsing the finite element method, three-dimensional models of a number of periodic blunt and sharp notches subjected to tension loading are carried out. The aim of this research is to investigate the thickness effect on the location of maximum stress and notch stress intensity factor (NSIF) of corresponding blunt and sharp periodic notches respectively. With this aim, a wide range of notch geometries are examined. While for two-dimensional plates weakened by periodic notches some results are available in the literature, this paper first faces with the problem of three-dimensional cases. The total of about 100 geometrical configurations are investigated. It is found that, the effect of plate thickness of periodic notched components can be characterized by its relative value with respect to the depth of the notch (H/t). For the blunt periodic notches with relatively higher values of H/t ratio, the value of the maximum tensile stress is located near the free surface. On the contrary for lower values of H/t, it is placed at the middle plane. The same behaviour is observed for sharp periodic notches in terms of notch stress intensity factors
Some recent developments on the application of the strain energy density to shallow threaded plates with sharp notches
No full textIn this study, the main advantages of the strain energy density (SED) approach and some recent applications of the SED to the fatigue analysis of welded joints are reviewed. In addition, the paper investigates the scale effect in the threaded plates with sharp notches subjected to tension loading. Some closed form expressions for evaluation of the notch stress intensity factors (NSIFs) of periodic sharp notches, obtained by SED approach, are employed. The new expressions are applicable to narrow notches when the ratio between the notch depth and the plate width, t/W, is lower than 0.025 providing very accurate results. The NSIF ratio of two scaled geometries of periodic sharp notches is a function of averaged SED in the control volume embracing the middle notch tip. The new results are very useful for the assessment under fatigue loadin
On three-dimensional stress analysis of periodic notched plates under tension
No full textBy using the finite element method, three-dimensional models of a number of periodic blunt and sharp notches subjected to tension loading are investigated. The aim of this research is to investigate the thickness effect on the location of maximum stress and notch stress intensity factor (NSIF) of corresponding blunt and sharp periodic notches respectively. With this aim, different number of periodic notches as well as different notch opening angles are examined. While for two-dimensional plates weakened by periodic notches some results are available in the literature, this paper first faces the problem of three-dimensional cases. A total of about 100 geometrical configurations are investigated. It is found that, the effect of plate thickness of periodic notched components can be characterized by the relative value with respect to the depth of the notch (H/t). For the blunt periodic notches with relatively higher values of H/t ratio, the value of the maximum tensile stress is located near the free surface. On the contrary for lower values of H/t, it is placed at the middle plane. The same behaviour is observed for sharp periodic notches in terms of notch stress intensity factors
Effects of geometrical parameters on the stress field of three-dimensional plates weakened by periodic notches
No full textIn this study, through-the-thickness stress field and the maximum stress location of flat plates with periodic blunt notches by using the three-dimensional finite element analysis are investigated. In particular, the effect of variation of six geometrical parameters as: the plate thickness, the ratio of notch depth to width of the plate, the pitch of periodic notches, the notch opening angle and the notch tip radius on the through the thickness stress state and location of the maximum stress are studied. More than five hundred three-dimensional geometrical configurations are analyzed. Results of this study show that, for relatively thin plates, the maximum stress of middle notch appears to be at the mid-plane and that confirms the plane stress assumption of two-dimensional finite element models. However, increasing the plate thickness leads to a shift in the location of maximum stress from the mid-plane towards the free surface of the plate. Increasing the number of notches with the purpose of decreasing stress values at the notch tip is possible, just when the pitch of the notches is relatively small. Furthermore, among the mentioned geometrical parameters, pitch variation (in particular for the case of relatively thin plates) has the most important influence on the location of the maximum tensile stress at the middle notch of periodic notched plate
STRESS ANALYSIS OF PERIODIC SHARP V-NOTCHED PLATES BY USING STRAIN ENERGY DENSITY APPROACH
No full textThe Strain Energy Density approach for stress analysis of periodic sharp-notched flat plates under tension
No full textThree-Dimensional Finite Element Analysis of Single-Lap Joints: Effect of Adhesive Thickness and Poisson's Ratio
No full textThree-dimensional (3D) elastic stress distributions in the vicinity of overlap corners of single-lap joints are investigated. A detailed 3D finite element (FE) model is carried out to study the intensity of the in-plane and out-of-plane stress distributions along the plate width direction. The effects of adhesive thickness and Poisson's ratio are also studied. The FE results show the presence of coupled modes at the overlap corners of the joint. In particular, sharp increment of out-of-plane fracture mode very near the lateral free surface of the joint is worth notin
Simple New Expressions for the Notch Stress Intensity Factors in an Array of Narrow V-Notches Under Tension
No full textTaking advantage of some recent closed form expressions for the strain energy density in a control volume embracing the notch tip, some simple expressions are derived for the Notch Stress Intensity Factors of an infinite array of double symmetric lateral notches and edge notches under tension loading. The new expressions are applicable to narrow notches when the ratio between the notch depth and the plate width, a/W, is lower than 0.025 providing very accurate results. © 2012 Springer Science+Business Media B.V
Stress concentration factors of periodic notches determined from the strain energy density
No full textStress concentration factors (SCFs) of a number of flat plates and round bars with periodic U- and V-notches are evaluated. Tension, bending and torsion loadings are considered in the investigation. The main objective of the investigation is to take advantage of the local strain energy density (SED) averaged on a control volume surrounding the tip of the middle notch and to estimate the SCF of each component by using a relatively coarse mesh. The unique advantage of SED method is the most prominent application of such a technique in the current study. Systematic FE simulations by considering a wide range of notch acuity and relative frequency of periodic U- and V-notch components are performed. More than two hundred and fifty models have been examined. The results of this study are compared with those provided by other researchers in the past and recent literature. Two new expressions of the notch depth reduction factor for the case of normal stresses (tension and bending) and torsion are also proposed to match the results from SED approach. © 2011 Elsevier Ltd. All rights reserved
MODE SELECTION IN REDUCED-ORDER MODELS FOR ULTRASONIC HORNS UNDER LONGITUDINAL VIBRATION
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