scholarly journals Analysis of Intensity of Singular Stress Fields at the End of a Cylindrical Inclusion under Asymmetric Uniaxial Tension.

2000 ◽  
Vol 66 (644) ◽  
pp. 735-740
Author(s):  
Nao-Aki NODA ◽  
Takao GENKAI ◽  
Yu-Ichiro KUMAGAE
2003 ◽  
Vol 70 (4) ◽  
pp. 487-495 ◽  
Author(s):  
N.-A. Noda ◽  
T. Genkai ◽  
Q. Wang

In short fiber reinforced composite it is known that the singular stress at the end of fibers causes crack initiation, propagation, and final failure. The singular stress field is controlled by the generalized stress intensity factors defined at the end of the inclusion. In this study the stress intensity factors are discussed for an elastic cylindrical inclusion in an infinite body under (A) asymmetric uniaxial tension in the x direction, and (B) symmetric uniaxial tension in the z direction. These problems are formulated as a system of integral equations with Cauchy-type or logarithmic-type singularities, where densities of body force distributed in infinite bodies having the same elastic constants as those of the matrix and inclusion are unknown. In the numerical analysis, the unknown body force densities are expressed as fundamental density functions and weight functions. Here, fundamental density functions are chosen to express the symmetric and skew-symmetric stress singularities. Then, the singular stress fields at the end of a cylindrical inclusion are discussed with varying the fiber length and elastic ratio. The results are compared with the ones of a rectangular inclusion under longitudinal and transverse tension.


2021 ◽  
pp. 1-22
Author(s):  
Nitish Kumar ◽  
Syed Nizamuddin Khaderi

Abstract We investigate the mechanics of the detachment of an inclined micro-pillar adhered to a dissimilar substrate when subjected to a combination of an axial load and end moment. When the micro-pillar has adhered to the substrate, singular stress fields exist at the bi-material corners. The order of singularity is estimated using asymptotic analysis. The first two terms in the asymptotic expansion lead to singular stress fields. The magnitude of the singularity is evaluated in terms of the elastic mismatch between the pillar and substrate and the micro-pillar inclination. The asymptotic stress due to the moment loading is more sensitive to the micro-pillar inclination when compared to that due to the axial loading. They are insensitive to the micro-pillar inclination when the micro-pillar is rigid when compared to the substrate. A short interfacial crack is further assumed to exist at the bi-material corner. This crack is embedded in the corner singularity region and is loaded by the singular fields due to axial and bending loads. A boundary layer analysis is performed on the singular zone to estimate the stress intensity factor when a short crack embedded in it is subjected to the singular fields. The stress intensity factors are also calculated for a long interfacial crack at the bi-material corner, which extends beyond the singular zone. Using the above results, we investigate the detachment of the inclined micro-pillar under the combination of an axial load and end moment.


2018 ◽  
Vol 67 (12) ◽  
pp. 1073-1079 ◽  
Author(s):  
Nao-Aki NODA ◽  
Dong CHEN ◽  
Rei TAKAKI ◽  
Akane INOUE ◽  
Guowei ZHANG ◽  
...  

2011 ◽  
Vol 413 ◽  
pp. 223-228
Author(s):  
Xue Cheng Ping ◽  
Xing Li ◽  
Xiao Xiang Xu

Failure in anisotropic/isotropic bi-materials starts at the interface, and the interfacial failure is of interest to some engineering fields such as automobile and aviation industry. Many researchers have done a lot of research on this field, but many did not consider a specific stress component near the interface corner tip as a parameter of a failure criterion. Kun Cheol Shin, introducted a failure criterion for anisotropic/isotropic bi-materials problem with a wedge. But the process of obtaining the singular stress fields of anisotropic/isotropic bi-materials is complex. To solve this problem, we have taken a new method which is from Xuecheng-Ping and M.-C. Chen.The method is new, which is based on displacement and more easily in calculating the stress and displacement fields surrounding a wedge tip than before. Through this method, we establish a criterion base on the-plan. The failure criterion can be used not only to predict stress intensities of co-cured double lap joints that with thermal and mechanical load, but also to predict stress intensities of co-cured double lap joints that with different materials or lap length. And we describe the process of calculating singular stress fields and stress intensities of co-cured double lap joints with a wedge that consists of glass fiber reinforced composites and steel adherends.


2001 ◽  
Vol 53 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Jörg Hohe ◽  
Wilfried Becker ◽  
Sanjib Goswami

2020 ◽  
Vol 23 (2) ◽  
pp. 155-165
Author(s):  
Tatsujiro Miyazaki ◽  
Keisuke Sato ◽  
Takahiro Fujiwara ◽  
Nao-Aki Noda ◽  
Yoshikazu Sano

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