scholarly journals Coupled Numerical Method for Modeling Propped Fracture Behavior

2021 ◽  
Vol 11 (20) ◽  
pp. 9681
Author(s):  
Tamás Lengyel ◽  
Attila Varga ◽  
Ferenc Safranyik ◽  
Anita Jobbik
Keyword(s):  
Fluid Dynamics ◽  
Finite Element Method ◽  
Finite Element ◽  
Fracture Behavior ◽  
Elastic Behavior ◽  
Hydraulic Fractures ◽  
Coupled Models ◽  
Fracture Conductivity ◽  
The Impact ◽  
Element Method

Hydraulic fracturing is a well-known production intensification technique in the petroleum industry that aims to enhance the productivity of a well drilled mostly in less permeable reservoirs. The process’s effectiveness depends on the achieved fracture conductivity, the product of fracture width, and the permeability of the proppant pack placed within the fracture. This article presents an innovative method developed by our research activity that incorporates the benefit of the Discrete—and Finite Element Method to describe the in situ behavior of hydraulic fractures with a particular emphasis on fracture conductivity. DEM (Discrete Element Method) provided the application of random particle generation and non-uniform proppant placement. We also used FEM (Finite Element Method) Static Structural module to simulate the elastic behavior of solid materials: proppant and formation, while CFD (Computational Fluid Dynamics) module was applied to represent fluid dynamics within the propped fracture. The results of our numerical model were compared to data of API RP-19D and API RP-61 laboratory measurements and findings gained by publishers dealing with propped fracture conductivity. The match of the outcomes verified the method and encouraged us to describe proppant deformation and embedment and their effect as precisely as possible. Based on the results, we performed sensitivity analysis which pointed out the impact of several factors affecting proppant embedment, deformation, and fracture conductivity and let one be aware of a reasonable interpretation of propped hydraulic fracture operation. However, DEM–CFD coupled models were introduced regarding fracturing before, to the best of our knowledge, the developed workflow of coupling DEM–FEM–CFD for modeling proppant-supported fracture behavior has not been applied yet, thus arising new perspectives for explorers and engineers.

A Fracture Mechanics Based Parametric Study of the Copper-to-Copper Direct Thermo-Compression Bonded Interface Using Finite Element Method

2013 ◽  
Author(s):  
Ah-Young Park ◽  
Satish Chaparala ◽  
Seungbae Park
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Parametric Study ◽  
Initial Crack ◽  
Bonding Interface ◽  
Interface Condition ◽  
Large Temperature ◽  
Bonded Interface ◽  
The Impact ◽  
Element Method

Through-silicon via (TSV) technology is expected to overcome the limitations of I/O density and helps in enhancing system performance of conventional flip chip packages. One of the challenges for producing reliable TSV packages is the stacking and joining of thin wafers or dies. In the case of the conventional solder interconnections, many reliability issues arise at the interface between solder and copper bump. As an alternative solution, Cu-Cu direct thermo-compression bonding (CuDB) is a possible option to enable three-dimension (3D) package integration. CuDB has several advantages over the solder based micro bump joining, such as reduction in soldering process steps, enabling higher interconnect density, enhanced thermal conductivity and decreased concerns about intermetallic compounds (IMC) formation. Critical issue of CuDB is bonding interface condition. After the bonding process, Cu-Cu direct bonding interface is obtained. However, several researchers have reported small voids at the bonded interface. These defects can act as an initial crack which may lead to eventual fracture of the interface. The fracture could happen due to the thermal expansion coefficient (CTE) mismatch between the substrate and the chip during the postbonding process, board level reflow or thermal cycling with large temperature changes. In this study, a quantitative assessment of the energy release rate has been made at the CuDB interface during temperature change finite element method (FEM). A parametric study is conducted to analyze the impact of the initial crack location and the material properties of surrounding materials. Finally, design recommendations are provided to minimize the probability of interfacial delamination in CuDB.

scholarly journals New CZM for Interfacial Crack Growth

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Huifen Peng ◽  
Yujie Song ◽  
Ye Xia
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crack Growth ◽  
Interface Crack ◽  
Interfacial Crack ◽  
Structure Design ◽  
Zone Model ◽  
Simulation Results ◽  
The Impact ◽  
Element Method

The cohesive zone model (CZM) has been widely used for numerical simulations of interface crack growth. However, geometrical and material discontinuities decrease the accuracy and efficiency of the CZM when based on the conventional finite element method (CFEM). In order to promote the development of numerical simulation of interfacial crack growth, a new CZM, based on the wavelet finite element method (WFEM), is presented. Some fundamental issues regarding CZM of interface crack growth of double cantilever beam (DCB) testing were studied. The simulation results were compared with the experimental and simulation results of CFEM. It was found that the new CZM had higher accuracy and efficiency in the simulation of interface crack growth. At last, the impact of crack initiation length and elastic constants of material on interface crack growth was studied based on the new CZM. These results provided a basis for reasonable structure design of composite material in engineering.

scholarly journals Evaluate the Impact of Cold Wave on Face Slab Cracking Using Fuzzy Finite Element Method

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Dongjian Zheng ◽  
Lin Cheng ◽  
Yanxin Xu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Drop ◽  
Extension Principle ◽  
Cold Wave ◽  
Prevention Measures ◽  
Fuzzy Variables ◽  
Fuzzy Finite Element ◽  
The Impact ◽  
Element Method

We use fuzzy finite element method (FEM) to analyze the impact of cold wave on face slab cracking of a concrete-faced rockfill dam (CFRD). The static response of dam and the temperature field of face slab are calculated using deterministic FEM since some observed and test data can be obtained. Some parameters of Goodman contact element between face slabs and cushion material are selected as fuzzy variables, and the fuzzy FEM is used to calculate fuzzy stress of face slab. The fuzzy FEM is implemented using vertex method based on the extension principle. Through the analysis of two selected calculation cases of cold wave, it is shown that the calculated cracking direction and cracking zone caused by thermal stress are similar to those of the observed cracks. This proves that the cold wave that caused swift air temperature drop is an important reason for the cracking of face slab. According to these analysis results, some cracking prevention measures are then proposed.

Fracture Mechanics of Architecture Dependent Fracture in Trabecular Bone Using the Cohesive Finite Element Method

2007 ◽  
Author(s):  
Vikas Tomar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Trabecular Bone ◽  
Fracture Behavior ◽  
Bone Microstructure ◽  
Tissue Properties ◽  
Rate Dependent ◽  
Microdamage Accumulation ◽  
Element Method ◽  
Rate Of Loading

Trabecular bone fracture is closely related to the trabecular architecture and microdamage accumulation. Micro-finite element models have been used to investigate the elastic and yield properties of trabecular bone but have only seen limited application in modeling the microstructure dependent fracture of trabecular bone, [1, 2]. In the presented research a cohesive finite element method (CFEM) based approach that can be used to model microstructure and loading rate dependent fracture in trabecular bone is developed for the first time. The emphasis is on understanding the effect of the rate of loading and its correlation with the bone microstructure on the microdamage accumulation and fracture behavior in the trabecular bone. Analyses focus on understanding the effect of the rate of loading, change in bone tissue properties with aging, and their correlation with the bone microstructure on the microdamage accumulation and the fracture behavior in the trabecular bone.

Performance Evaluation of Spring for the Vehicle Suspension System Using the Nonlinear Finite Element Method

2014 ◽  
Vol 635-637 ◽  
pp. 594-597
Author(s):  
Byeong Soo Kim ◽  
Byung Young Moon ◽  
Sung Kwan Kim
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Suspension System ◽  
Nonlinear Finite Element ◽  
Nonlinear Finite Element Method ◽  
Air Spring ◽  
Rubber Sleeve ◽  
The Impact ◽  
Element Method

Air spring is used for the suspension system and it affects the vehicle stability and riding comfort by improving the impact-relief, braking, and cornering performance. Air Spring is comprised of the upper plate, lower plate, and rubber sleeve. Rubber sleeve is the composite material, which is made up of combination of rubber and Nylon, and the characteristics are changed according to the shape of rubber-sleeve, the angle of reinforcement cord. In this study, the distribution of internal stresses and the deformation of rubber composite material are analyzed through the nonlinear finite element method. The result showed that the internal maximum stresses and deformations about the changes of cord angle caused the more the Young's modulus decrease, the more maximum stress reduced.

Mathematical Simulation of Rigid Pile Composite Foundation with Lateral Unloading

2013 ◽  
Vol 368-370 ◽  
pp. 756-759
Author(s):  
Jing Ma ◽  
Wen Sheng Chen ◽  
Xue Feng Hu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mathematical Simulation ◽  
Horizontal Displacement ◽  
Composite Foundation ◽  
The Finite Element Method ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation ◽  
The Impact ◽  
Element Method

Based on the Finite Element Method ,a model has been built to study the impact of rigid pile composite foundation with lateral unloading,then obtained a conclusion about the horizontal displacement during excavating.

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