Study on the Mechanism of the Impactor-Bit-Rock Interaction Using 3D FEM Analysis

2011 ◽  
Vol 189-193 ◽  
pp. 2280-2284 ◽  
Author(s):  
Yong Tao Fan ◽  
Zhi Qiang Huang ◽  
De Li Gao ◽  
Qin Li ◽  
Hai Yan Zhu
Keyword(s):  
Finite Element ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Transmission Efficiency ◽  
Air Pressure ◽  
Geophysical Prospecting ◽  
3D Fem ◽  
Element Analysis ◽  
Rock Interaction

To reveal the mechanism of the impactor-bit-rock interaction in geophysical prospecting percussion drilling, considering the coupling effect of the static pressure, impact force and rotary cutting, constructing the physical model of the impactor-bit-rock interaction, and using the finite element methods (FEM), three-dimensional (3D) model of the impactor-bit-rock interaction is established. Using the finite element analysis software (ANSYS/LS-DYNA), the 3D FEM analysis of the impactor-bit-rock interaction is carried out when compressed air pressure is 0.8 MPa, 0.9 MPa, 1.0 MPa, 1.1 MPa and 1.2 MPa respectively. The results show that: the energy transmission efficiency when piston impacts bit under different air pressure is not high and it should be improved further, bit can not fragment rock until it is impacted by piston, it is found that the best air pressure is 1.0 MPa when the impactor and bit are used to drill granite according to the volume of the fragmented rock and the depth of the crater, the speed and displacement on the radial direction of the piston which should be reduce even eliminate are very harmful. The results are further useful to extend the applications of the geophysical prospecting impactor and hammer bit.

Influence of temperature and strain rate on the longitudinal compressive crashworthiness of 3D braided composite tubes and finite element analysis

2016 ◽  
Vol 26 (7) ◽  
pp. 1003-1027 ◽  
Author(s):  
Xianyan Wu ◽  
Qian Zhang ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Rate ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Composite Tubes ◽  
Element Analysis ◽  
Impact Compression ◽  
Mechanical Coupling ◽  
The Impact

This article reports the longitudinal compressive crashworthiness of three-dimensional four-step circular braided carbon/epoxy composite tubes at temperatures of 23, −50, and −100℃ under strain rate ranging from 340 to 760/s both experimentally and finite element analysis. The experimental results showed that the compression strength, stiffness, and specific energy absorption increased with the decrease in temperature and with the increase in strain rate. It also showed that, the compressive damage morphologies were sensitive to the change in temperature and strain rate. A coupled thermal-mechanical numerical analysis was conducted to find the thermo/mechanical coupling effect on the compressive crashworthiness of the three-dimensional composite tube. The temperature distributions in the braided preform and the resin during the impact compression were also calculated through finite element analysis. From the finite element analysis results, the inelastic heat generation was seen to be more in the preform than the matrix and its distribution and accumulation led to the damage progress along the loading direction.

Study on 3d Flexible Pipe FEM Analysis by Spangler Theory

2013 ◽  
Vol 850-851 ◽  
pp. 821-824 ◽  
Author(s):  
Jun Xiao ◽  
Xiao Yu Zhang ◽  
Jian Zhong Chen ◽  
Zhuo Qiu Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Earth Pressure ◽  
Fem Analysis ◽  
Flexible Pipe ◽  
Element Analysis ◽  
Element Simulation ◽  
Complicated Process ◽  
Vertical Earth Pressure

Earth pressure can be divided into three kinds of load form by Spangler theory: vertical earth pressure, bed reaction and horizontal lateral pressure. According to Spangler theory, the level of static earth pressure presents a parabolic distribution in central angle bon both sides of the tubes. Used the glass steel pipe as the specific research object, Spangler theory applied to the three-dimensional buried tube model for finite element analysis, the analysis is divided into two situations: (1) the same soil, finite element analysis of different pipe diameter; (2) the same tube diameter, finite element analysis of different soil. This method can reasonably reflect the interaction of soil and structure, it is feasible. The complicated process of the finite element simulation of tube soil interaction can be avoided.

Three-Dimensional Finite Element Analysis of Dental Implant Threads

2018 ◽  
Vol 876 ◽  
pp. 138-146
Author(s):  
Aswin Yodrux ◽  
Nantakrit Yodpijit ◽  
Manutchanok Jongprasithporn
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dental Implant ◽  
Three Dimensional ◽  
Biomechanical Analysis ◽  
3D Fem ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
States Patent

This paper presents the use of Three-Dimensional Finite Element Method (3D-FEM) for biomechanical analysis on dental implant prosthetics. This research focuses on three patents of threads of dental implant systems from United States Patent and Trademark Office (USPTO) and two new conceptual design models. The three-dimensional finite element analysis is performed on dental implant models, with compressive forces of 50, 100, and 150 N, and a shear force of 20 N with the force angle of 60 degrees with the normal line respectively. The Stress and displacement analysis is conducted at four different areas (abutment, implant, cortical bone, and cancellous bone). Findings from this research provide guidelines for new product design of dental implant prosthetics with stress distribution and displacement characteristics.

Generalized Plane Strain Study of Rotational Autofrettage of Thick-Walled Cylinders—Part II: Numerical Evaluation

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
S. M. Kamal ◽  
M. Perl
Keyword(s):  
Finite Element ◽  
Plane Strain ◽  
Numerical Evaluation ◽  
Hoop Stress ◽  
Three Dimensional ◽  
Fem Analysis ◽  
3D Fem ◽  
Theoretical Evaluation ◽  
Gun Barrel ◽  
Generalized Plane Strain

The theoretical modeling of the rotational autofrettage of a thick-walled cylinder based on the generalized plane strain assumption has been presented in part I of the paper. In order to access the potentiality of the proposed theoretical model, the numerical evaluation of the analytical solutions is important. This part of the paper presents numerical evaluation of the generalized plane strain model for typical thick-walled cylinders. The residual hoop stress generated in the rotational autofrettage of a typical gun barrel is compared with the residual hoop stresses in the conventional hydraulic and swage autofrettage processes. Comparison shows that the rotationally autofrettaged gun barrel is capable of producing the same level of compressive residual hoop stress at the inner surface as that of the hydraulic autofrettage. In order to corroborate the analytical solution, a three-dimensional finite element method (3D FEM) analysis of the rotational process is carried out in ANSYS finite element package and the results are compared with the theoretical results. The comparison shows a good matching of the results between the theoretical evaluation and the 3D FEM analysis. Finally, a short feasibility analysis of the rotational autofrettage process of typical cylinders is carried out for the practical realization of the process.

Study on Mechanism of Hammer Bit and Rock Interaction in Geophysical Prospecting Percussion Drilling

2011 ◽  
Vol 291-294 ◽  
pp. 2266-2271
Author(s):  
Zhi Qiang Huang ◽  
Qin Li ◽  
Yong Tao Fan ◽  
Zhen Qiang Wei ◽  
Hai Yan Zhu
Keyword(s):  
Finite Element ◽  
Effective Stress ◽  
Impact Force ◽  
Coupling Effect ◽  
Oil And Gas Industry ◽  
Drilling Process ◽  
Geophysical Prospecting ◽  
Rock Interaction ◽  
Impact Effect ◽  
Percussion Drilling

Percussion drilling has been widely used in oil and gas industry, yet it still has some shortcomings, such as severe damages to drilling tools, low energy transferring efficiency and low rock-fragmenting efficiency. Thus it is necessary to reveal the mechanism of interactions between the hammer bit and rock in geophysical prospecting percussion drilling. Taking account of the coupling effect of the Weight on Bit (WOB), impact force and rotary torque, this paper constructed a Finite Element Method (FEM) model using the finite element analysis software (ANSYS/LS-DYNA) and conducted a computer simulation of bit-rock interaction under rotating and simple impact effect, which showed the rock-fragmenting process of hammer bit and the curves of volume-time and depth-time of craters as well as the effective stress-time curves of the centre tooth, second-row tooth and peripheral tooth. The results showed that: the percussion drilling process under rotating impact effect is characterized as four fundamental processes; the crater depth mainly depends on impact force rather than rotary torque; the crater created under rotating impact effect is twice the volume of that under impact effect; the effective stress of each tooth changes severely: the stress of second-row tooth is the largest, centre tooth the second, and peripheral tooth the smallest. This study provided a guide for the structural optimization of hammer bit and general applications of percussion drilling.

scholarly journals Application of the finite element method to the design of an ankle orthosis

2021 ◽  
Vol 2130 (1) ◽  
pp. 012013
Author(s):  
D Stefańczak ◽  
J Gajewski ◽  
M Rogala
Keyword(s):  
Finite Element ◽  
Low Cost ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Body Part ◽  
The Body ◽  
Design Stage ◽  
Mechanical Resistance ◽  
Three Dimensional Model ◽  
Element Analysis

Abstract AFO (Ankle-Foot Orthosis), which covers the ankle and foot, protects and supports the ankle joint as well as the structures around it. It contributes to the maintenance of the correct gait cycle. Owing to orthoses, the functional capacity of the body part is significantly improved, and so is the quality of life for the user. Personalized orthoses, which are adapted to the anatomy of the user, are more and more often produced by the additive methods. The use of 3D printing for the manufacturing medical devices is becoming increasingly common due to the low cost of the whole process, short production time and the possibility of the product personalization. One of the stages in manufacturing AFOs with the additive method is to create a three-dimensional model of the orthosis in CAD software. Finite element analysis was performed to assess the mechanical properties of the orthosis. The influence of geometry and the materials used were investigated with FEM analysis software. As a result of structural analysis during the design stage, the assessment of the medical device in terms of its durability and mechanical resistance without putting the user at risk is possible. On the basis of the obtained results, the structure strength was compared.

scholarly journals Lightning Performance of Copper-Mesh Clad Composite Panels: Test and Simulation

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 727 ◽  
Author(s):  
Hu ◽  
Yu
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Element Model ◽  
Laminated Plates ◽  
Lightning Strike ◽  
Element Analysis ◽  
Three Dimensional Finite Element ◽  
Copper Mesh

：According to simulation lightning experiments and eddy current analysis results, a three-dimensional finite element model of composite laminated plates with shield is established. By applying electric-thermal boundary and the coupling relationship between them, the lightning strike damage results under the protection of shield are realistically simulated with the commercial finite element analysis software, ABAQUS. Considering the coupling effect of heat, electricity, and force during lightning strike, the load distribution field of copper mesh and carbon fiber panel with lightning current inducted is analyzed. Comparing the thermal stress distribution of the specimen surface under various current loads, it is shown that the stress of carbon fiber panel is significantly lower than the one of the copper screen when the specimen structure suffers heavy current, since the copper network plays a role of endergonic protection. Simulation data are consistent with the test results, thus the method can be used for other similar research.

Parameter studies and verifications on three-dimensional finite element analysis of rigid pavements

2004 ◽  
Vol 31 (5) ◽  
pp. 782-796 ◽  
Author(s):  
Ying-Haur Lee ◽  
Hsin-Ta Wu ◽  
Shao-Tang Yen
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Element Model ◽  
Prediction Equation ◽  
Element Analysis ◽  
Dimensionless Variable ◽  
Shell Elements ◽  
Rigid Pavements ◽  
Element Selection

The main objective of this study was to conduct in-depth parameter studies and verifications on three-dimensional (3-D) finite element (FEM) analysis of rigid pavements. A systematic analytical approach was utilized and implemented in a Visual Basic software package to study the effects of mesh fineness and element selection. The deflection and stress convergence characteristics of various 3-D shell and solid elements were investigated. Several guidelines in mesh fineness and element selection were developed and recommended. Using the principles of dimensional analysis, an additional dimensionless variable (h/a, where h is the thickness of the slab and a is the radius of the applied load) was identified and verified to have a substantial influence on ABAQUS runs using either 3-D shell elements or 3-D solid elements. Separate 3-D FEM stress and deflection databases were developed using all dimensionless variables. An example critical stress predictive model was developed. Together with the existing two-dimensional FEM research findings, a tentative stress prediction equation was proposed to illustrate its possible applications.Key words: rigid pavement, finite element model, stress, deflection, design, evaluation.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

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