On the determination and application of cod to epoxy-bonded aluminium joints

1979 ◽  
Vol 14 (2) ◽  
pp. 37-42 ◽  
Author(s):  
C L Chow ◽  
C W Woo ◽  
J L Sykes
Keyword(s):  
Crack Opening ◽  
Load Control ◽  
Yield Model ◽  
Cohesive Fracture ◽  
Element Analysis ◽  
Testing Conditions ◽  
Strip Yield Model ◽  
Dimensional Finite Element ◽  
Good Agreement

A method of analysis is presented for the determination of crack-opening-displacements (COD) and their application to aluminium—Araldite joint systems. Use is made of a beam-on-elastic-foundation (BEF) model, which is extended to represent the physical system. It is seen that, in conjunction with this, the Dugdale ‘strip-yield’ model solution may be combined to characterize interfacial or cohesive fracture cases. Fracture toughness values, based on both load and displacement control testing conditions, are examined and show that the equation derived for the load-control model yields greater accuracy. Results of the proposed method are compared with those obtained by a two-dimensional, finite-element analysis and are found to be in good agreement. The validity of the proposed analysis is further verified by experimental observations employing conventional compliance methods for both interfacial and cohesive fracture modes.

Determination of J-Integral Using the Load-COD Record for Circumferential Through-Wall Cracked Pipes

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Nam-Su Huh ◽  
Yun-Jae Kim
Keyword(s):  
Crack Opening ◽  
Estimation Method ◽  
J Integral ◽  
Opening Displacement ◽  
Element Analysis ◽  
Load Line ◽  
Load Line Displacement ◽  
Η Factor ◽  
J Estimation

The present paper provides experimental J estimation equation based on the load-crack opening displacement (COD) record for testing the circumferential through-wall cracked pipe under combined tension and bending. Based on the limit analysis and the kinematically admissible rigid-body rotation field, the plastic η-factor for the load-COD record is derived and is compared with that for the load-load line displacement record. Comparison with the J results from detailed elastic-plastic finite element analysis shows that the proposed method based on the load-COD record provides reliable J estimates even for shallow cracks (small crack angle), whereas the conventional approach based on the load-load line displacement record gives erroneous results for shallow cracks. Thus, the proposed J estimation method could be recommended for testing the circumferential through-wall cracked pipe, particularly with shallow cracks.

Determination of crack-opening displacement by the method of caustics

1974 ◽  
Vol 9 (3) ◽  
pp. 197-205 ◽  
Author(s):  
P S Theocaris
Keyword(s):  
Crack Opening Displacement ◽  
Mechanical Characteristics ◽  
Crack Opening ◽  
Crack Tip ◽  
External Loading ◽  
Small Scale ◽  
Opening Displacement ◽  
Cracked Plates ◽  
Good Agreement

A new experimental technique based on the method of caustics is presented for the measurement of the distance between the lips of a crack near the crack-tip. The two parts of the caustic formed by reflections from the front and rear faces of the specimen lie at a distance from each other. The gap between these parts depends on the total c.o.d. (crack-opening displacement), that is the initial opening and the opening due to loading, as well as on the optical and mechanical characteristics of the material By increasing the external loading of the cracked plate, the gap between the parts of the caustic was changed and this gap measured the instantaneous c.o.d. due to loading. The method was applied to the measurement of small c.o.d.s. due to small-scale loading, with satisfactory results. Therefore it can certainly be used to measure c.o.d.s at large loading steps, up to fracture, because the gap between the parts of the caustic becomes significant and easy to measure. Measurements with cracked plates made of p.m.m.a. (polymethylmethacrylate) and polycarbonate showed that the results obtained are in good agreement with theory. Thus, it has been proved that the method of caustics yields a very sensitive means for measuring c.o.d.s, especially in small-scale deformations, where measurement of c.o.d by conventional methods is inaccurate. A great advantage of the method is that it measures the c.o.d.s at a well defined region, which always remains near to the crack tip.

Applicability Evaluation of the Weight Function Based Strip Yield Model for an Embedded Crack Problems

2009 ◽  
Author(s):  
Koji Gotoh ◽  
Yukinobu Nagata
Keyword(s):  
Weight Function ◽  
Surface Crack ◽  
Crack Opening ◽  
Yield Model ◽  
Uniform Loading ◽  
Strip Yield Model ◽  
Synthesis Methodology ◽  
Embedded Crack ◽  
Applicability Evaluation ◽  
Perfect Plastic

Applicability evaluation of the developed weight function based strip yield model for an embedded crack by applying the slice synthesis methodology in elastic-perfect plastic bodies under monotonic uniform loading is performed. Although the weight function based strip yield model for a part-through semi-elliptical surface crack in an elastic-perfect plastic bodies under monotonic uniform loading was proposed by Daniewicz and Aveline (2000), applicable geometries of cracked bodies is limited. Their proposed strip yield model treats only a semi-elliptical surface crack in semi-infinite bodies. Besides, quantitative investigations of the applicability seem to be insufficient. The authors proposed the improved strip yield model with slice synthesis methodology for an embedded crack, which enables to treat the finite boundary problems. By applying proposed model, the back surface effect of the crack opening behaviour and the plastic zone growth can be considered. The validity of improved strip yield model for embedded cracks is confirmed by comparing crack opening profiles under some crack geometries with elastic-plastic finite element analyses.

Three-Dimensional Finite Element Analysis on Open-Die Block Forging Design

1992 ◽  
Vol 114 (4) ◽  
pp. 459-464 ◽  
Author(s):  
Chinghua Hung ◽  
Shiro Kobayashi
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Rigid Plastic ◽  
Flat Bottom ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Die Set ◽  
Cylindrical Workpiece ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Three-dimensional rigid-plastic finite element method was used to analyze the practice of open-die block forging, focusing on the effects of die configurations and forging pass designs. Four combinations of die configurations were investigated: conventional flat dies, top flat/bottom V-shaped dies, and double V-shaped dies with 120 and 135 deg included angles. Two different pass designs, 90 and 180 deg rotation angles between succeeding passes, were applied to each die set. The results include the magnitude and distribution of effective strains along the center line of the cylindrical workpiece and the final shape of the workpiece. Good agreement was observed in comparison with experimental data from physical modeling method, and several suggestions were made for choosing suitable dies.

scholarly journals FINITE ELEMENT ANALYSIS OF SHADED POLE MOTOR BASED ON MAXWELL2D

2021 ◽  
Vol 25 (Special) ◽  
pp. 1-115-1-220
Author(s):  
Adnan J. Kazem ◽  
◽  
Amer M. Ali ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Induction Motor ◽  
Single Phase ◽  
Two Dimensional ◽  
Element Analysis ◽  
Analytical Results ◽  
Dimensional Finite Element ◽  
Good Agreement

Shaded pole induction motor is one of the simplest and least expensive types of single-phase motors, but one of the most difficult to analyze. In this paper, we adopted a two-dimensional finite element method 2DFEM, which is one of the most accurate methods to analyze such motors. We used Ansys Maxwell2D software with assist of AutoCAD software in modeling and analyzing a reluctance-augmented shaded pole motor. The 2DFEM results of torques and currents for this motor obtained from Maxwell2D were compared with the analytical results and appeared a good agreement.

A finite-element method applied to predicting fatigue-crack growth

1973 ◽  
Vol 8 (4) ◽  
pp. 294-304 ◽  
Author(s):  
D Walton ◽  
N J Woodman ◽  
E G Ellison
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Plastic Material ◽  
Crack Opening ◽  
Plastic Zone Size ◽  
Yield Model ◽  
Opening Displacement ◽  
Element Analysis ◽  
Linear Elastic ◽  
Elastic Plastic Material

A finite-element analysis is presented to determine the stress and strain fields at and near the tip of a crack in an elastic-plastic material. These results, together with estimates of the crack opening displacement and plastic-zone size, are compared with equivalent values obtained from linear elastic fracture mechanics and the strip-yield model. Finally the finite-element-strain field data are used in a model which predicts the rates of fatigue-crack propagation; these correlate well with experimental results.

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