Crack-profile shapes formed under a Vickers indent pyramid

1987 ◽  
Vol 6 (6) ◽  
pp. 721-723 ◽  
Author(s):  
S. L. Jones ◽  
C. J. Norman ◽  
R. Shahani
Keyword(s):  
2020 ◽  
Vol 64 (1-4) ◽  
pp. 621-629
Author(s):  
Yingsong Zhao ◽  
Cherdpong Jomdecha ◽  
Shejuan Xie ◽  
Zhenmao Chen ◽  
Pan Qi ◽  
...  

In this paper, the conventional database type fast forward solver for efficient simulation of eddy current testing (ECT) signals is upgraded by using an advanced multi-media finite element (MME) at the crack edge for treating inversion of complex shaped crack. Because the analysis domain is limited at the crack region, the fast forward solver can significantly improve the numerical accuracy and efficiency once the coefficient matrices of the MME can be properly calculated. Instead of the Gauss point classification, a new scheme to calculate the coefficient matrix of the MME is proposed and implemented to upgrade the ECT fast forward solver. To verify its efficiency and the feasibility for reconstruction of complex shaped crack, several cracks were reconstructed through inverse analysis using the new MME scheme. The numerical results proved that the upgraded fast forward solver can give better accuracy for simulating ECT signals, and consequently gives better crack profile reconstruction.


MRS Advances ◽  
2018 ◽  
Vol 3 (37) ◽  
pp. 2159-2168
Author(s):  
Rehema Ndeda ◽  
S. E. M Sebusang ◽  
R. Marumo ◽  
Erich O. Ogur

ABSTRACTMacroscopic strength of the rock depends on the behavior of the micro constituents, that is, the minerals, pores and crack profile. It is important to determine the effect of these constituents on the overall behavior of the rock. This study seeks to estimate the effective elastic properties of granite using the finite element method. A representative volume element (RVE) of suitable size with spherical inclusions of different distribution is subjected to loading and the effective elastic properties determined. The results are compared to those obtained from analytical methods. The elastic properties are obtained in both the axial and transverse direction to account for anisotropy. It is observed that there is congruence in the results obtained both analytically and numerically. The method of periodic microstructures exhibits close agreement with the numerical results.


Jurnal METTEK ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. 43
Author(s):  
Dwi Payana ◽  
I Made Widiyarta ◽  
Made Sucipta

Beban gesek pada permukaan sebuah benda dapat menimbulkan panas pada permukaan kontak benda tersebut. Semakin besar beban gesek yang terjadi, suhu pada permukaan material akan menjadi lebih tinggi. Peningkatan suhu permukaan yang semakin tinggi dapat mempengaruhi sifat mekanis permukaan material dan tentunya dapat berimplikasi terhadap mekanisme kegagalan pada permukaan material tersebut, seperti kegagalan aus dan kegagalan retak. Pada penelitian ini, uji kekerasan dilakukan pada material dengan suhu permukaan tertentu. Permukaan material baja karbon sedang dipanaskan dengan variasi suhu yaitu mulai dari suhu kamar sampai dengan 300ºC, kemudian dilakukan uji Vicker’s. Tingkat kekerasan dan profil indentasi Vickers pada permukaan material dengan variasi suhu tersebut kemudian diinvestigasi. Friction load on the surface of an object can cause heat on the contact surface of the object. The larger the frictional load occurs, the temperature on the surface of the material will become higher. Increased surface temperatures can further affect the mechanical properties of the material surface and can certainly have implications for the failure mechanisms on the surface of the material, such as wear failure and crack failure. In this study, hardness tests were performed on materials with certain surface temperature. The surface of the carbon steel material is being heated with temperature variations ranging from room temperature up to 300ºC, then Vicker's test. The degree of hardness and Vickers indent profile on the surface of the material with the temperature variation is then investigated.


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