Numerical Analysis of Bridge Caisson Foundation due to Riverbed Erosion

2013 ◽  
Vol 405-408 ◽  
pp. 342-348
Author(s):  
Wen Tsung Liu ◽  
Chia Chyi Chang ◽  
Kuei Hsiang Cheng ◽  
Chen Wei Chi

Keywords: Scour Depth, Water flow Force, Finite Element Method ABSTRACT. In recent years, the researches on the impact stability of piers based on river erosion are concerned in Taiwan. Therefore, it is an important issue to estimate accurately the scour depth, to calculate the water flow force on bridge pier, and to establish the close mechanism of bridge for saving lives. This research is a case study on Paulon Bridge by finite element method (FEM) Plaxis 3D Foundation for simulating analysis the caisson foundation in bridge pier scour. Firstly, we infer the flood level, the speed of flow in the different frequency year, the whole bridge safety coefficient, and the inclination angle of pile based on the simulating analysis to build the warning system. We compare the data by FEM and observing data in order to confirm the validity of FEM.

Author(s):  
Ah-Young Park ◽  
Satish Chaparala ◽  
Seungbae Park

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.


1988 ◽  
Vol 7 (4) ◽  
pp. 174-183
Author(s):  
G. J. Van Tonder ◽  
J. F. Botha

The present investigation is mostly concerned with the contribution that the finite-element method can make towards the simulation of ground water flow. After a brief introduction to the finite element method, it is applied to the Grootfontein dolomitic aquifer near Mafikeng/Mmabatho. This aquifer yields water for irrigation purposes as well as water for the township. By utilizing the available information a good flow model was constructed for this aquifer. The model is considered calibrated and verificated.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Huifen Peng ◽  
Yujie Song ◽  
Ye Xia

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Dongjian Zheng ◽  
Lin Cheng ◽  
Yanxin Xu

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.


2014 ◽  
Vol 635-637 ◽  
pp. 594-597
Author(s):  
Byeong Soo Kim ◽  
Byung Young Moon ◽  
Sung Kwan Kim

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.


2013 ◽  
Vol 368-370 ◽  
pp. 756-759
Author(s):  
Jing Ma ◽  
Wen Sheng Chen ◽  
Xue Feng Hu

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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