Evaluation and criterion determination of the low- k thin film adhesion by the surface acoustic waves with cohesive zone model

2017 ◽  
Vol 399 ◽  
pp. 599-607 ◽  
Author(s):  
Xia Xiao ◽  
Haiyang Qi ◽  
Xiaole Sui ◽  
Takamaro Kikkawa
Keyword(s):  
Thin Film ◽  
Acoustic Waves ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Surface Acoustic Waves ◽  
Zone Model ◽  
Film Adhesion ◽  
Thin Film Adhesion ◽  
Low K

Existence and Convergence Questions in Computational Modelling of Crack Growth in Brittle and Quasi-Brittle Materials

2016 ◽  
Vol 258 ◽  
pp. 157-160 ◽  
Author(s):  
Jiří Vala
Keyword(s):  
Crack Growth ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Computational Modelling ◽  
Brittle Materials ◽  
Zone Model ◽  
Static Tests ◽  
Materials Used ◽  
Proper Analysis

Computational modelling of the crack growth in brittle and quasi-brittle materials used in mechanical, civil, etc. engineering applies the cohesive zone model with various traction separation laws; determination of micro-mechanical parameters comes then from static tests, microscopic observation and numerical calibration. Although most authors refer to ill-possedness and need of artificial regularization in inverse problems (identification of material parameters), some difficulties originate even in nonlinear formulations of direct and sensitivity problems. This paper demonstrates the possibility of proper analysis of the existence of a weak solution and of the convergence of a corresponding numerical algorithm for such model problem, avoiding non-physical assumptions.

Modeling of Cohesive Zone and Crack Growth in Ni-Al Thin-Film Using MD-XFEM Based Approach

2010 ◽  
Author(s):  
Gaurav Singh ◽  
Vijay Kumar Sutrakar ◽  
D. Roy Mahapatra
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Solid Phase ◽  
Md Simulations ◽  
Failure Behavior ◽  
Mode I ◽  
Zone Model ◽  
Al Thin Film

Intermetallic alloys of Ni-Al have important applications in high temperature anti-corrosive coatings, engine and turbine related materials, and shape memory devices. Predicting failure behavior of these materials is difficult using purely continuum model, since several of the material constants are complicated functions of micro and nano-scale details. This includes solid-solid phase transformation. In the present paper, a framework for analyzing fracture in two-dimensional planar domain is developed using a molecular dynamic (MD) simulation and extended finite element method (XFEM). The framework is then applied to simulate fracture in Ni-Al thin-film. Effect of Ni Al crystallites of various sizes on the mechanical properties is analyzed using direct MD simulations. Initiation and growth of crack under slow (quasi-static) tensile loading in mode-I condition is considered. Mechanical properties at room temperature are estimated via MD simulations, which are further used in the XFEM at the continuum scale. A cohesive zone model for the macroscopic XFEM model is implemented, which directly bridges the molecular length-scale via MD framework. Numerical convergence studies are reported for mode-I crack in initially single crystal B2 Ni-Al thin film.

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