A three-dimensional model for a graphene guided SH-SAW sensor using finite element method

Author(s):  
I. Nikolaou ◽  
H. Hallil ◽  
O. Tamarin ◽  
C. Dejous ◽  
D. Rebiere
Author(s):  
Patrick D. Lea ◽  
Charbel Farhat ◽  
Kevin G. Wang

This work extends and generalizes a recently developed fluid-structure coupled computational framework to model and simulate fluid-induced failure and fracture. In particular, a novel surface representation approach is proposed to represent a fractured fluid-structure interface in the context of embedded boundary method. This approach is generic in the sense that it is applicable to many different computational fracture models and methods, including the element deletion (ED) technique and the extended finite element method (XFEM). Two three-dimensional model problems are presented to demonstrate the salient features of the computational framework, and to compare the performance of ED and XFEM in the context of fluid-induced failure and fracture.


2010 ◽  
Vol 132 (11) ◽  
Author(s):  
X. Zheng ◽  
Q. Xue ◽  
R. Mittal ◽  
S. Beilamowicz

A new flow-structure interaction method is presented, which couples a sharp-interface immersed boundary method flow solver with a finite-element method based solid dynamics solver. The coupled method provides robust and high-fidelity solution for complex flow-structure interaction (FSI) problems such as those involving three-dimensional flow and viscoelastic solids. The FSI solver is used to simulate flow-induced vibrations of the vocal folds during phonation. Both two- and three-dimensional models have been examined and qualitative, as well as quantitative comparisons, have been made with established results in order to validate the solver. The solver is used to study the onset of phonation in a two-dimensional laryngeal model and the dynamics of the glottal jet in a three-dimensional model and results from these studies are also presented.


2015 ◽  
Vol 1125 ◽  
pp. 432-436 ◽  
Author(s):  
Sandro Mihradi ◽  
Calvindoro Zeus Abdiwijaya ◽  
Tatacipta Dirgantara ◽  
Andi Isra Mahyuddin

In the present research, three-dimensional models of above-knee prosthesis, consist of socket, four-bar linkage knee, pylon and foot, are developed. These models have to fulfill criteria such as stability, ability to withstand up to 90 kg of bodyweight, ability to flex up to 130 degree, easy for maintenance, simple manufacturing process, affordable and yet reliable. As the first step of development, these models were evaluated using finite element method software to determine whether or not the design has fulfilled strength criteria. The results show that the last iteration of the three dimensional model of the knee prosthesis has satisfied the criteria.


2010 ◽  
Vol 39 ◽  
pp. 550-554 ◽  
Author(s):  
Xin Fan ◽  
Mao Hui Pan ◽  
Cheng Song Zhang

Connecting rod fatigue in a certain type of diesel engine is analyzed by using finite element analysis method and the FEM software ANSYS. According the actual working conditions, the three-dimensional model with multi-body contact is established to simulate the contact between the connecting rod parts; By using APDL language programming, the work load on the connecting rod, calculated according all the link work loads, is applied to the connecting rod bearing and bushing through the oil film pressure distribution. By finite element method structural strength of the connecting rod was calculated, that can effectively guide the connecting rod design, which has been proved by practice.


2004 ◽  
Vol 471-472 ◽  
pp. 844-849 ◽  
Author(s):  
Ping Ma ◽  
Cheng Xiang Liao ◽  
M.L. Duan ◽  
J.K. Li ◽  
D.N. Li ◽  
...  

Balance for high speed motorized spindle is most important, it will influence the dynamic behavior of the high speed machine tools. In this paper, the GD-IV high speed spindle is introduced. In order to improve its balance accuracy, the step interference fit is developed to connect the rotor and the shaft. The interference fitted assembly has been modeled theoretically, the analysis highlights that the tolerance of the interference fit consists of the static section and dynamic section, the static section is determined by the transmitting torque while the dynamic section is determined by the centrifugal force. The Calculation of interference fit for the GD-IV spindle shows that the dynamic section is about 4.5 times larger than the static. Furthermore, the three dimensional model of the step interference fit between the shaft and the rotor has also been built up with finite element method and the stress distribution on the mating surface has been calculated. The results show that the maximum stress occurring near the chamfer region of the internal surface of the rotor is up to 235 MPa lower than the permissible material stress 278 MPa, so that the design of the step interference fit is reliability and safety.


Author(s):  
C Chen ◽  
R Kovacevic

Friction stir welding (FSW) is a solid-state jointing technology, in which the butted plates are heated, plasticized and jointed locally by the plunged probe and shoulder moving along the joint line. The residual stresses due to the thermomechanical performance of the material and the constraint of the welded plates by the fixture are one of main concerns for this process. A prediction of the clamping force applied on the plates during FSW is expected to be helpful in controlling the residual stresses and weld quality. Furthermore, the prediction of the force history in FSW will be beneficial to understand the mechanics of the process and to provide valid models for controlling the process, especially in the case of robotic FSW. In this paper, a three-dimensional model based on a finite element method is proposed to study the thermal history and stress distribution in the weld and, subsequently, to compute mechanical forces in the longitudinal, lateral and vertical directions. The proposed model includes a coupled thermomechanical modelling. The parametric investigation of the effects of the tool rotational and longitudinal speed on the longitudinal, lateral and vertical forces is also conducted in order to compute the appropriate clamping force applied on the plates. Measurements by the load cells in the longitudinal, lateral and vertical directions are presented and reveal a reasonable agreement between the experimental results and the numerical calculations.


Vestnik IGEU ◽  
2019 ◽  
pp. 12-23
Author(s):  
V.A. Gorbunov ◽  
N.A. Lonshakov ◽  
I.V. Alekseyev ◽  
M.N. Mechtayeva

A problem to be solved now is determining the hub nodes of hydraulic losses arising during the operation of power plant equipment. Detection of such points directly by measuring devices on the operating equipment is impossible as it is difficult to access many elements of the flow part of the units. Development of digital models of equipment allows simulating these processes and with a high degree of accuracy determining the location of increased hydraulic losses. The aim of this work is to determine the magnitude and localization of hydraulic losses in the control valve of the steam turbine. The analysis of steam turbine valve operation has been carried out based on thermodynamic, hydraulic and mechanical parameters, which are taken directly during the operation of the power plant by standard control and measuring devices. The obtained information was processed by the finite element method in the Ansys and SolidEdge Flow Simulation programs and by three-dimensional modeling in the SolidEdge software package. We have obtained a three-dimensional model of the control valve and determined the fields of pressure, velocity, etc. distribution in the volume of the control valve under different operating conditions by the finite element method. During the processing of the obtained information, we found excessive energy losses of water vapor arising during its throttling in the control valve. Such losses produce a significant effect on the power developed by the turbine pump. During the operation of the drive turbine, the pressure losses of the working medium in the steam distribution system vary in the range of 300–500 kPa (37–62 % of the initial pressure before the control valve). The goal set in the work has been fully achieved. Verification of the developed three-dimensional model was made on the basis of the operational parameters taken during the steam turbine operation. The application of the work results, both for modernizing the existing units and designing new equipment, will increase the efficiency of electric energy production at the power unit of the station.


Author(s):  
E.V. Patraev ◽  
M.S. Vakulin ◽  
Y.I. Gordeev ◽  
V.B. Yasinsky

The paper deals with the design of the cutting part of complex-profile cutters with high productivity and surface quality. Numerical experiments carried out using the finite element method made it possible to determine the stresses and strains in the layer of the cut material when machining with multifaceted milling cutters of a new type and indirectly estimate the specific cutting forces. The required dimensions and shape of the cutting wedge are set with account for various geometric parameters of the cutting part, properties of the workpiece material, and cutting conditions. This made it possible to obtain a three-dimensional model of an end mill with a trapezoidal tooth and 700 cutting edges. Experimental studies also showed a change in the morphology of chips with a size of about 2 microns, which is in good agreement with the results of preliminary estimates by the finite element method. The productivity of processing with milling cutters of a new design can be improved by increasing the number of single cutting cycles up to4000–6000 s–1.


Sign in / Sign up

Export Citation Format

Share Document