Prediction of the Plastic Fracture Mechanical Properties on Metallurgical Composite Bimetallic Tube with Axial Crack

2011 ◽  
Vol 467-469 ◽  
pp. 1367-1371 ◽  
Author(s):  
Li Yun Zheng ◽  
Chun Qiang Li ◽  
Li Hui Wang ◽  
Ya Feng Song
Keyword(s):  
Mechanical Properties ◽  
Crack Growth ◽  
Residual Strength ◽  
Crack Depth ◽  
Failure Stress ◽  
Pressure Tube ◽  
Tube Model ◽  
Element Analysis ◽  
Plastic Failure ◽  
Axial Crack

Based on the finite element analysis software ABAQUS, the CT specimens of bimetallic material and the metallurgical composite bimetallic pressure tube with axial crack were simulated on the fracture mechanical properties, after that the crack growth residual strength and the plastic failure stress of the metallurgical composite bimetallic pressure tube model were obtained. The results indicate that the crack growth residual strength generates near the crack tip and the crack growth residual strength of the pressure tube model is smaller than the CT specimens. Meanwhile, the plastic failure stress values obtained from the CT specimens and the pressure tube model are basically consistent with the theoretical calculative values. With the crack depth a increasing, the plastic failure stress values will be reduced. For the same crack depth, the plastic failure stress values of the pressure tube model are slightly lower than the CT specimens and the theoretical calculative values.

Stress Intensity Factors for Cracks in Conventional S-N Fatigue Specimens

1996 ◽  
Vol 118 (2) ◽  
pp. 203-207
Author(s):  
T. P. O’Donnell
Keyword(s):  
Stress Intensity ◽  
Crack Growth ◽  
Fatigue Testing ◽  
Axial Stress ◽  
Crack Depth ◽  
Three Dimensional ◽  
Axial Displacement ◽  
Element Analysis ◽  
Displacement Boundary ◽  
Specimen Diameter

Stress intensity values for cracks growing in conventional fatigue specimens are determined, with emphasis on the end constraint conditions associated with S-N fatigue testing. Three-dimensional finite element analysis methods are used to analyze thumbnail-shaped cracks in cylindrical geometries. Crack front straightening due to the increased bending introduced as crack growth progresses is included in the models. Because relatively stiff fatigue test machines prevent rotation at the clamped ends of test specimens, uniform axial displacement boundary conditions are imposed. Results for uniformly applied axial stress end conditions are also obtained for comparison. For crack-depth-to-specimen-diameter ratios over one-third, bending restraint induced in the specimens under applied axial displacement significantly reduces the resulting stress intensity relative to values computed for uniform end tension. The results are useful for evaluating crack growth in fatigue specimens within the limits of linear elastic fracture mechanics.

Failure Stress Analysis of Adhesive T-Joint under Moisture Condition

2015 ◽  
Vol 786 ◽  
pp. 94-98
Author(s):  
S. Nurhashima ◽  
Mohd Afendi ◽  
Basirom Izzawati ◽  
A. Nor ◽  
Abdul Rahman Abdullah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Hot Water ◽  
Failure Stress ◽  
Element Analysis ◽  
Moisture Condition ◽  
Lightweight Structures ◽  
Test Compression ◽  
The Finite Element Analysis ◽  
Good Agreement

The use of adhesive structural in joining application offers the great demand due to its many advantages such as lightweight structures and flexible design. However, moisture provides significant problem and adverse effect on degrading the adhesive. The strength of the adhesive reduces because mechanical properties are known to reduce also with moisture environment. Therefore, this paper discusses about the adhesive T-joint test on specimen within moisture condition and specimen without moisture, at room temperature. Additionally, this study also analyses the failure stress when load is applied for both exposed conditions. Bulk specimens are compressed at room temperature, specimen without immersing in hot water, RT and specimen with immersing in three hot water conditions 80°C, 90°C, and 100°C at a constant time of 15 minutes. The adhesive of a 1.0mm thickness has been set for T-joint tensile test. Compression test revealed that mechanical properties of Young’s modulus decreased with the increase of water temperature. Experimental results indicated that the failure stress of adhesive T-joint at room temperature and 90°C was higher compared to that of specimen soaked in 80°C and 100°C of hot water. The behaviour of adhesive joint tests under static loading analysis of experiments and the finite element analysis using ANSYS 14.0 software have shown good agreement.

Advanced Finite Element Analysis (AFEA) Evaluation for Circumferential and Axial PWSCC Defects

2010 ◽  
Author(s):  
D.-J. Shim ◽  
S. Kalyanam ◽  
E. Punch ◽  
T. Zhang ◽  
F. Brust ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Crack Growth ◽  
Crack Front ◽  
Nodal Point ◽  
Nuclear Industry ◽  
Element Analysis ◽  
Weld Residual Stress ◽  
Axial Crack

The Advanced Finite Element Analysis (AFEA) methodology has been developed by the US NRC and the nuclear industry to evaluate the natural crack growth of primary water stress corrosion cracking (PWSCC) in nickel-based alloy materials. The AFEA methodology allows the progression of a planar crack subjected to typical SCC-type growth laws by calculating stress intensity factors at every nodal point along the crack front, and incrementally advancing the crack front in a more natural manner. This paper describes the enhancements that have been made to the existing AFEA methodology. The most significant enhancement was the feature to evaluate axial crack growth where the crack was contained within the susceptible material. In this paper, this methodology was validated by performing an AFEA evaluation for the axial crack that was found in the V.C. Summer hot leg dissimilar metal weld. Other enhancements to the AFEA methodology include; upgrade to the PipeFracCAE© software developed by Engineering Mechanics Corporation of Columbus, feature to handle non-idealized circumferential through-wall cracks, mapping of weld residual stress for crack growth, and determination of limiting crack size using elastic-plastic J-integral analysis that included secondary stress (weld residual stress and thermal transient stress) effects.

Spar Corner Radius Integrity for the A400M Wing

2006 ◽  
Vol 3-4 ◽  
pp. 197-204 ◽  
Author(s):  
Tim Edwards ◽  
Jeremy Thompson
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Release ◽  
Crack Growth ◽  
Failure Stress ◽  
Shear Stresses ◽  
Bending Moments ◽  
Element Analysis ◽  
Initial Development ◽  
Corner Radius

The paper focuses on the structural integrity of the corner radius of the carbon fibre composite, ‘C’-section spar for the Airbus A400M wing. The corner radius is subject to opening moments generated by internal wing box fuel pressures. The low inter-lamina strength of composites makes de-lamination of the corner of prime concern. The paper describes initial development of analytical techniques to calculate the through-thickness tensile stresses and inter-lamina shear stresses developed in a corner radius under applied bending moments and transverse shear forces. A test programme is also described, aimed at the determination of the failure moment of curved laminates under pure bending moments. Using the analytical expressions developed, a through-thickness failure stress is calculated from the failure moments. A variation of the failure stress with specimen thickness is indicated, showing that thicker specimens fail at higher inter-lamina stresses – a characteristic that must be exploited in the design of the spar. Using finite element analysis of the test configuration, in conjunction with virtual crack extension techniques, it is demonstrated that, at the failure load, a constant rate of strain energy release accompanies inter-lamina crack growth in the different test specimens. A critical energy release rate for uncontrolled crack growth is thus established, which is used, in conjunction with further finite element analysis, to predict the failure stress of specimens with different values of thickness and corner radius. It is concluded that this fracture mechanics approach to integrity can be applied to the A400M spar corner and to similar aircraft structures. Recommendations for further testing and correlation with analysis are proposed to strengthen the theoretical basis for such integrity assessments.

Finite Element Analysis of Reinforced Concrete Beams with Exterior FRP Shell

2011 ◽  
Vol 243-249 ◽  
pp. 1461-1465
Author(s):  
Chuan Min Zhang ◽  
Chao He Chen ◽  
Ye Fan Chen
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Contact Interface ◽  
Accurate Calculation ◽  
Element Analysis

The paper makes an analysis of the reinforced concrete beams with exterior FRP Shell in Finite Element, and compares it with the test results. The results show that, by means of this model, mechanical properties of reinforced concrete beams with exterior FRP shell can be predicted better. However, the larger the load, the larger deviation between calculated values and test values. Hence, if more accurate calculation is required, issues of contact interface between the reinforced concrete beams and the FRP shell should be taken into consideration.

scholarly journals Effect of Elevated Temperature on Mechanical Properties of High-Volume Fly Ash-Based Geopolymer Concrete, Mortar and Paste Cured at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Jun Zhao ◽  
Kang Wang ◽  
Shuaibin Wang ◽  
Zike Wang ◽  
Zhaohui Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
High Volume ◽  
Sem Analysis ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Exposure Temperature

This paper presents results from experimental work on mechanical properties of geopolymer concrete, mortar and paste prepared using fly ash and blended slag. Compressive strength, splitting tensile strength and flexural strength tests were conducted on large sets of geopolymer and ordinary concrete, mortar and paste after exposure to elevated temperatures. From Thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM) test results, the geopolymer exhibits excellent resistance to elevated temperature. Compressive strengths of C30, C40 and C50 geopolymer concrete, mortar and paste show incremental improvement then followed by a gradual reduction, and finally reach a relatively consistent value with an increase in exposure temperature. The higher slag content in the geopolymer reduces residual strength and the lower exposure temperature corresponding to peak residual strength. Resistance to elevated temperature of C40 geopolymer concrete, mortar and paste is better than that of ordinary concrete, mortar and paste at the same grade. XRD, TGA and SEM analysis suggests that the heat resistance of C–S–H produced using slag is lower than that of sulphoaluminate gel (quartz and mullite, etc.) produced using fly ash. This facilitates degradation of C30, C40 and C50 geopolymer after exposure to elevated temperatures.

scholarly journals Assessing the Flexural Properties of Epoxy Composites with Extremely Low Addition of Cellulose Nanofiber Content

2020 ◽  
Vol 10 (3) ◽  
pp. 1159 ◽  
Author(s):  
Yingmei Xie ◽  
Hiroki Kurita ◽  
Ryugo Ishigami ◽  
Fumio Narita
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Flexural Modulus ◽  
Strengthening Mechanism ◽  
Short Fiber ◽  
Cellulose Nanofiber ◽  
Resin Matrix ◽  
Element Analysis ◽  
Epoxy Resin Matrix ◽  
The Matrix

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

ANSYS Simply Supported Deep Beams Based on the Study of Mechanical Properties

2013 ◽  
Vol 351-352 ◽  
pp. 782-785
Author(s):  
Yong Bing Liu ◽  
Xiao Zhong Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Mechanical Model ◽  
Work Performance ◽  
Deep Beam ◽  
Analysis Software ◽  
Deep Beams ◽  
Element Analysis ◽  
Simply Supported ◽  
Force Characteristics

Established the mechanical model of simply supported deep beam, calculation and analysis of simple supported deep beams by using finite element analysis software ANSYS, simulated the force characteristics and work performance of the deep beam. Provides the reference for the design and construction of deep beams.

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