scholarly journals Application of a Geotextile in the Treatment of Post-Subsidence in Karst Areas

2021 ◽  
Vol 11 (24) ◽  
pp. 11826
Author(s):  
Di Wu ◽  
Chen Luo ◽  
Yuankun Li ◽  
Yanxin Yang ◽  
Yihuai Liang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Tensile Force ◽  
Surface Settlement ◽  
Soil Pressure ◽  
Element Analysis ◽  
Anchorage Length ◽  
Karst Areas ◽  
Two Factors ◽  
Insight Into ◽  
Stable Area

The use of a geotextile to treat subgrade subsidence after subsidence has occurred is investigated in this paper. To optimize the anchorage length and buried depth of the geotextile and evaluate the influences of the two factors on subgrade subsidence treatment, finite element analysis is performed and validated with existing model tests. The soil pressure, displacement, tensile force and deformation of the geotextile are studied. The results showed that the geotextile prevented an upward development of subsidence and stabilized the upper soil. The increase of the anchorage length of the geotextile transferred greater soil pressure from the subsidence to a stable area, induced a greater tensile force in the geotextile, and resulted in less soil displacement. As the anchorage length of the geotextile increased from 375 mm to 1500 mm, the surface settlement was effectively reduced from 1.05% to 34.18% when comparing to the situation without a geotextile. As the buried depth of the geotextile increased from 2 m to 6 m, the percentage of surface settlement was effectively reduced from 29.14% to 65.91% when comparing with the settlement corresponding to a buried depth of 2 m. It is suggested that the anchorage length of a geotextile should be the length of the subsidence with respect to width and that the buried depth of the geotextile should be 3–4 m for subsidence treatment. This provides insight into the treatment of sinkholes using geosynthetic approaches in karst areas.

Three Turnaround Heat Treating Studies

2003 ◽  
Author(s):  
Jaan Taagepera ◽  
Marty Clift ◽  
D. Mike DeHart ◽  
Keneth Marden
Keyword(s):  
Heat Treatment ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Heat Treating ◽  
Element Analysis ◽  
Stress Profiles ◽  
Insight Into

Three vessel modifications requiring heat treatment were analyzed prior to and during a planned turnaround at a refinery. One was a thick nozzle that required weld build up. This nozzle had been in hydrogen service and required bake-out to reduce the potential for cracking during the weld build up. Finite element analysis was used to study the thermal stresses involved in the bake-out. Another heat treatment studied was a PWHT of a nozzle replacement. The heat treatment band and temperature were varied with location in order to minimize cost and reduction in remaining strength of the vessel. Again, FEA was used to provide insight into the thermal stress profiles during heat treatment. The fmal heat treatment study was for inserting a new nozzle in a 1-1/4Cr-1/2Mo reactor. While this material would ordinarily require PWHT, the alteration was proposed to be installed without PWHT. Though accepted by the Jurisdiction, this nozzle installation was ultimately cancelled.

The Effects of Varying Frictional Contact Boundary Conditions in Finite Element Analysis of Mandibular Parasymphyseal Fracture

2007 ◽  
Author(s):  
Victor Caraveo ◽  
Scott Lovald ◽  
Tariq Khraishi ◽  
Jon Wagner ◽  
Brett Baack
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Frictional Contact ◽  
Biological Tissues ◽  
Fracture Repair ◽  
Design Tool ◽  
Contact Boundary ◽  
Element Analysis ◽  
Accurate Design ◽  
Insight Into

FE modeling of biological tissues and physiological behavior is now becoming common practice with the improvement in finite element analysis (FEA) software and the significant increase in capability of computing resources. There are many uses for FEA of this nature, one of which has been simulating the mechanical behavior of implant devices for fracture repair. FE analysis offers insight into the mechanistic behavior of fixation plates used in rigid internal fixation and, if modeled carefully, could eventually become an accurate design tool.

Reduction of Thermal Stress - Part III: UBM and Passivation Thickness Optimization

2017 ◽  
Vol 2017 (1) ◽  
pp. 000694-000698
Author(s):  
Raj Sekar Sethu ◽  
Salil Hari Kulkarni ◽  
How Ung Ha ◽  
Kok Heng Soon
Keyword(s):  
Finite Element Analysis ◽  
Solder Ball ◽  
Coefficient Of Thermal Expansion ◽  
Thickness Optimization ◽  
Wafer Level ◽  
Element Analysis ◽  
Wafer Level Packaging ◽  
Two Factors ◽  
Process Factors ◽  
Significant Factors

Abstract Integration of Back End Of Line (BEOL) CMOS technologies with Wafer Level Packaging (WLP) is challenging, as mismatch of Coefficient of Thermal Expansion (CTE) between materials can result in thermo-mechanical induced cracking. This is especially true during reflow cooling of wafers after the solder ball attach process. Factors that contribute towards cracking can be from both the BEOL as well the WLP process steps. Finite Element Analysis (FEA) of such designs can help identify possible root causes early in the design process and i.e. before actual fabrication. This would help save valuable prototyping & testing costs. In Part III of this series of FEA studies, two factors i.e. silicon nitride thickness (from the BEOL process), and the Under Bump Metalization (UBM) thickness (from the WLP process) were identified as significant factors in changing the maximum first principal stress levels in the passivation layer.

Investigation of Performance of a Femoral Implant With a Plug Using Finite Element Analysis

1999 ◽  
Author(s):  
Taiming Chu ◽  
Deanna Y. Carstarphen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Critical Section ◽  
Cobalt Chromium ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Hip Function ◽  
Femoral Implants ◽  
Insight Into ◽  
Head Neck

Abstract A Finite Element Analysis was performed on the critical section of a titanium alloy femoral implant coupled with a cobalt-chromium Dall-Miles Cable Grip System (DMCGS). The critical section of the implant is defined at the hole where the wires of the DMCGS are threaded. Two models were generated for the analysis. The first model consisted of the critical section with a cobalt-chromium plug filled in at the hole. The second model consisted of the critical section without the plug in the hole. The models used in the study were based on a design developed by Howmedica Incorporated (called the “head-neck replacement”). One static simulation was performed on each model. This simulation represented the early stance phase of normal walking. The wires used in the simulations were pre-tensioned. The preliminary results of the analysis showed that the stresses in the model with the added plug were lower than those in the model without the plug. This indicated that a plug added to a femoral implant adjoined with the Dall-Miles Cable Grip System reduces the stress concentrations at the hole. Furthermore, the results of the study will provide insight into the modifications on design of femoral implants. This may well lead to an improvement in implant performance and better aid in the restoration of hip function for arthritic patients.

Finite Element Analysis of the Soil Pressure in Sandy Soil at the Top of Pipe Culvert

2015 ◽  
Vol 744-746 ◽  
pp. 1077-1081
Author(s):  
Qi Yun Cheng ◽  
Yong Gang Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Hydraulic Structure ◽  
Relative Height ◽  
Engineering Analysis ◽  
Analysis Software ◽  
Soil Pressure ◽  
Element Analysis ◽  
Distribution Shape ◽  
Multiple Analysis

ANSYS is an engineering analysis software with a multiple analysis ability.It can be used to solve the structure, fluid, electric, electromagnetic fields and collision problems and so on.So it has been widely used in varied fields.Circular culvert is commonly used for water hydraulic structure in hydraulic engineering.The paper focuses on the study of culvert soil pressure at the top of the circle under the sand in the northern of China by using the Ansys finite element analysis software.Research shows that:When the elastic modulus and Poisson's ratio changes,the soil pressure distribution shape doesn’t obviously change;While the soil pressure and the relative height of precipitation have a certain relationship with the two indicators.

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