Finite Element Method Model Research Articles

Thermal Power and the Structural Parameters of a Wind Turbine Permanent Magnet Eddy Current Heater

Permanent magnet eddy current heating as a new type of wind energy utilization method, which is energy-saving, is zero-emission, and involves no pollution and a high utilization of wind energy, has attracted more and more attention. This paper deals with the simulation and optimal design of a permanent magnet eddy current heater (PMECH) driven by wind. Solid steel, closed-slot, and open-slot PMECH are proposed, and corresponding 2D finite element method (FEM) models are established. Using the skin depth concept, numerical analyses are conducted on the influence of the number, size, and position of copper strips on the thermal power of closed-slot and open-slot PMECHs, and the thermal power growth compared to solid steel PMECH. The results showed that there is an optimal value for stator wall thickness. When the air-gap length is 0.5 mm and the rotation speed is 200 and 1000 rpm, the optimal stator wall thickness is 16 and 9 mm, respectively. Compared to the influence of conductivity on thermal power, the influence of permeability is more significant. Compared with solid steel PMECH, both closed-slot and open-slot PMECH in a low-speed region can effectively improve thermal power, and the open slot has more obvious advantages. The maximum values of the thermal power growth (TPG) and thermal power growth rate (TPGR) of the closed-slot PMECH are 1.57 kW and 120.15%, respectively. The maximums of TPG and TPGR of the open-slot PMECH are 2.58 kW and 175.08%, respectively. The experimental results prove the validity of the analytical calculation.

Improvement of vibration response of a foundation resting on Salt-Encrusted Flat Soil by cement addition: a numerical investigation

ABSTRACT Excessive vibrations can negatively impact machinery performance by causing misalignment, decreased accuracy, increased wear and tear, and reduced overall operational efficiency. By conducting a numerical investigation on improving vibration response through cement addition to salt-encrusted flat soil, the study aims to enhance the performance and reliability of machine foundations, thereby optimizing machinery operation. The properties of untreated sabkha and cement-sabkha were calibrated to use in the Finite Element Method (FEM) model. The variables investigated have the thickness of cemented sabkha ratio, operation frequency, three types of subsoils (Sabkha and cemented sabkha of 5% and 10%), and vertical amplitude loading. The main findings revealed that the maximum shear modulus (Gmax) increases by 47% with a 5% to 10% increase in cement content. In addition, as the vibration’s frequency increases, the amplitude displacement is observed because the reflected waves become smaller for the foundation resting on cemented sabkha. The natural frequency rises as the thickness ratio and cement amount of cemented sabkha increase. The influence of the thickness ratio on displacement amplitude is considerable when the operation frequency is less than 20 hz. The study implies that engineers can optimize the design of machine foundations to achieve better performance and stability.

Research on Coordinated Relationship Between Deformation and Force in Shaft Foundation Pit Support Structures

In order to investigate the coordinated relationship between lateral deformation of the diaphragm wall and axial force of the internal strut, this paper first carried out a scaled model test on the mechanical features of a foundation pit support system based on a novel axial force servo device. Then, a finite element model was established to simulate the scaled model test, and the correctness of the finite element modeling approach was validated by comparing test results. After that, the same finite element modeling method was used to analyze the coordinated relationship between axial force and lateral deformation in the prototype foundation pit support structure. The results show that the axial force of the inner strut is negatively correlated with the lateral deformation in the diaphragm wall. The initial maximum lateral deformation in the diaphragm wall of the shaft foundation pit occurs at the bottom of the foundation pit, so changing the length of bottom strut simultaneously is the most effective way to adjust the mechanical behavior of the support structure. Under various support conditions, the maximum lateral deformation of the diaphragm wall in the prototype project is 0.59~0.66‰ of the total excavation depth of the foundation pit, and the maximum axial force of internal support is 11~30% of the yield load of a single steel strut.

Finite Element Simulation of Ti-6Al-4V Alloy Machining with a Grain-Size-Dependent Constitutive Model Considering the Ploughing Effect Under MQL and Cryogenic Conditions

The finite element modeling method has been widely applied in the modeling of the cutting process to characterize the instantaneous and microscale deformation mechanism that was difficult to obtain using physical experiments. The lubrication and cooling conditions, such as minimum quantity lubrication and cryogenic liquid nitrogen, affect the thermo-mechanical behaviors and machined surface integrity in the cutting process. In this work, a grain-size-dependent constitutive model was used to model orthogonal cutting for Ti-6Al-4V alloy with MQL and LN2 conditions. The cutting forces and chip morphologies that were measured in the cutting experiments of Ti-6Al-4V alloy were used to validate the simulated forces. The relative errors between the measured and simulated principal forces were less than 8%, while the relative errors of thrust forces were less than 19%. The predicted chip morphologies and surface grain refinement agreed well with the experimental results under the conditions with different uncut chip thicknesses and edge radii. Additionally, the relationship between the plastic displacement and grain refinement, as well as the microhardness and residual stresses under MQL and cryogenic conditions, were discussed. This work provides an effective modeling method for the orthogonal cutting of Ti-6Al-4V alloy to understand the mechanism of the plastic deformation and machined surface integrity under the MQL and LN2 conditions.

Performance of photovoltaic panels with different inclinations under uniform thermal loading

Integrating photovoltaic (PV) panels with different tilt angles in building envelopes or roofs is widely employed for environmental sustainability. However, little is known about the influence of different tilt angles on the thermal failure of the photovoltaic façades or roofs in fire conditions. A total of 15 four-edge shielded PV panels (300 × 300 × 4.7 mm3), with five different inclinations of 0°, 15°, 30°, 45° and 60°, were heated to fail using a uniform radiant panel. Measurements were taken to track glass thermal breakage, surface temperatures, incident heat flux and failure characteristics. The glass fracture and pyrolysis of the internal thermoplastic materials were observed under thermal radiation. The average breakage time of glass in PV panels showed an increasing trend with increasing inclination of the PV panels. Moreover, when the PV panels were tilted beyond 30°, the time to failure increased more significantly. The maximum temperature difference and heat flux that the PV panels can withstand were primarily measured within the range of 61–84 °C and 8–15 kW/m2, respectively. Finally, the test results were simulated by a finite element method (FEM) model, calculating the heat transfer and thermal stress of PV panels: the average errors concerning temperature distributions and failure times were smaller than 15 % compared with the experimental results.

Beam Local Stress Prediction Model for Incremental Launching Construction Based on SSA-SVR Algorithm

In the multi-point incremental launching construction process, without setting temporary piers at the mid-span, it is difficult to ensure the synchronization of the launching equipment at the same pier, which can easily cause the beam to deviate from the design axis, leading to changes in the stress of the beam. Calculating the local maximum stress of the beam when lateral deviation occurs is beneficial for establishing a reasonable and reliable threshold for controlling beam deviations. To address this issue, this paper utilizes a finite element model of the bridge under typical adverse conditions, simulating the lateral deviation and asynchronous jacking of the beam to explore stress variation patterns. The results show that the beam stress increases as the lateral deviation and jacking differences increase, severely affecting the structural safety. To overcome the inefficiency of the finite element modeling method when dealing with multiple working conditions and to establish a reasonable deviation control threshold, this study proposes a beam local stress prediction model under the combined influence of lateral deviation and jacking height differences based on the SSA-SVR algorithm. The model calculates the local maximum stress of the beam for 2500 sets of parameters. An engineering case analysis shows that the prediction model has high calculation accuracy, reliable results, fast computational speed, and high efficiency. Based on the stress prediction results, it is recommended to set the jacking height difference control threshold at 20 mm. When the jacking height difference is less than 20 mm, the local maximum stress value under the combined influence of both parameters should be less than the standard limit. The corresponding lateral deviation control threshold can be dynamically adjusted according to the actual travel difference recorded by the jacking equipment, with the control precision improved to 1 mm.

Damage analysis and assessment of concrete T-girder bridge based on fire scene numerical reconstruction

Fire is a sporadic disaster of concrete bridges, with diverse fire environments and complex damage mechanisms. Accurately evaluating the damage situation of concrete bridges after a fire is exceedingly challenging. This study formulates a damage analysis and assessment method based on the step-by-step and progressively deepening working principle. The method relies on fire scene numerical reconstruction and encompasses key technical aspects, including bridge detection and analysis during the fire incident, fire scene numerical reconstruction, and subsequent bridge damage assessment. Building upon these principles, the study utilizes results from the detection and analysis of the concrete T-girder bridge during a fire incident to establish Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) models for the numerical reconstruction of the fire scene. These models enable the calculation of varying temperature distributions and the evolution of the bridge under fire. Compared with the parameters obtained through the ISO834 method, the numerical reconstruction approaches not only enhances the accuracy of replicating the bridge combustion process but also enables the extraction of temperature field distribution patterns within the bridge fire space and its concrete components.

Performance evaluation of ALIP applying fully enclosed slot

ABSTRACT In nuclear energy systems, annular linear induction pump (ALIP) is regarded as an ideal device for transporting liquid metal. Developed pressure and efficiency are crucial indicators for evaluating performance of an ALIP, and enhancing these fac- tors is of utmost importance. This paper presents a 2D axisymmetric finite element method (FEM) model for efficiently predicting the performance of ALIP and a 3D FEM model to explore the implementation of a fully enclosed slot structure. The accuracy of the proposed models is validated by comparing the results with experi- mental data, complemented by empirical formulas in the post-processing phase. The continuous and discontinuous conditions of the pole pieces are analyzed using the 3D FEM, demonstrating that the fully enclosed slot structure can significantly enhance both developed pressure and efficiency, thereby improving the overall performance of the ALIP.

Widening the frequency bandgap and reducing thermal conductivity in phononic crystals by tuning structural parameters using a novel computational simulation method

AbstractThis paper introduces and models a phononic structure based on single-crystal silicon, aiming to investigate the width of its frequency bandgap and the impact of key parameters on thermal conductivity. The modeled phononic crystal structure features a periodic arrangement of cylindrical holes in a silicon matrix. This research holds the potential to enhance thermal management performance of thermal metamaterials. Utilizing a 3D finite element method (FEM) model in COMSOL, we have computed phonon dispersion to estimate thermal conductivity. The study systematically has explored the influence of phononic crystal parameters—specifically, porosity, lattice constant, and thickness—along with their interactions on both thermal conductivity and frequency bandgap width.A comprehensive investigation of these parameters has been conducted for their optimization to achieve the maximum frequency bandgap width and minimum thermal conductivity using the response surface method model. Eigenfrequencies and wave vector parameters are extracted from the finite element model using a MATLAB script. Subsequently, thermal conductivity is calculated through the Callaway–Holland model, a simplification of the Boltzmann transport equation (BTE).Our results indicate that the frequency bandgap begins to form at approximately 43% porosity for a lattice constant and thickness of 100 nm each. Furthermore, adjusting the parameters led to a significant reduction in thermal conductivity, decreasing from 43.89 W m−1 K−1 to 0.39 W m−1 K−1. The novelty of our research lies in thermal conductivity control of phononic crystal metamaterials through their parameter variations, or a predictive method of thermal conductivity and its parameter sensitivity. This study advances the state of the art in phononic crystal metamaterial research, contributing to improved thermal management performance by enlarging frequency bandgaps.Overall, our findings deepen the understanding of how porosity, lattice constant, and thickness influence thermal conductivity and frequency bandgap width. They offer valuable insights into optimizing phononic crystal parameters, enhancing thermal management performance, and designing more efficient and effective phononic crystal structures.

Prototype of a New Head Grabber for Robotic Strawberry Harvesting with a Vision System

This paper presents the design of a strawberry fruit head gripper unit, together with the concept of a control system for the operation of its mechanisms and vision system. The developed design consists of three specialised mechanisms: positioning, grasping, and cutting off of the fruit. A Finite Element Method (FEM) model was developed for the described design. Next, calculations were carried out, based on which the construction materials were selected. The key performance parameters of the functional model, built on the basis of the developed design concept, were verified under laboratory conditions. In tests carried out on the possible hematoma caused by exceeding the breaking stress induced by the pressure of the encompassing jaws on the fruit, it was found that none of the fruit tested suffered mechanical damage as a result of the sensor triggering force, and the average length of the trimmed stalk was approximately 14 mm. The designed head gripper, together with the proposed automation system, will contribute to improving harvesting precision, and this will favour a reduction in the quantitative and qualitative losses of the harvested crop. The experimental tests conducted under harvesting conditions showed a high efficiency of 95% in identifying ripe fruit, and the harvesting efficiency of the robotic arm was 90%.

A Comparative Study of Geometric Phase Change- and Sideband Peak Count-Based Techniques for Monitoring Damage Growth and Material Nonlinearity.

This work presents numerical modeling-based investigations for detecting and monitoring damage growth and material nonlinearity in plate structures using topological acoustic (TA) and sideband peak count (SPC)-based sensing techniques. The nonlinear ultrasonic SPC-based technique (SPC-index or SPC-I) has shown its effectiveness in monitoring damage growth affecting various engineering materials. However, the new acoustic parameter, "geometric phase change (GPC)" and GPC-index (or GPC-I), derived from the TA sensing technique adopted for monitoring damage growth or material nonlinearity has not been reported yet. The damage growth modeling is carried out by the peri-ultrasound technique to simulate nonlinear interactions between elastic waves and damages (cracks). For damage growth with a purely linear response and for the nonlinearity arising from only the nonlinear stress-strain relationship of the material, the numerical analysis is conducted by the finite element method (FEM) in the Abaqus/CAE 2021 software. In both numerical modeling scenarios, the SPC- and GPC-based techniques are adopted to capture and compare those responses. The computed results show that, from a purely linear scattering response in FEM modeling, the GPC-I can effectively detect the existence of damage but cannot monitor damage growth since the linear scattering differences are small when crack thickness increases. The SPC-I does not show any change when a nonlinear response is not generated. However, the nonlinear response from the damage growth can be efficiently modeled by the nonlocal peri-ultrasound technique. Both the GPC-I and SPC-I techniques can clearly show the damage evolution process if the frequencies are properly chosen. This investigation also shows that the GPC-I indicator has the capability to distinguish nonlinear materials from linear materials while the SPC-I is found to be more effective in distinguishing between different types of nonlinear materials. This work can reveal the mechanism of GPC-I for capturing linear and nonlinear responses, and thus can provide guidance in structural health monitoring (SHM).

Acoustic Black Holes ceiling for noise control on board cruise ships

Entertainment is one of the principal noise sources on board cruise ships. To ensure high comfort standards in cabins located above public areas, ceilings made by rockwool and honeycomb panels are used as acoustic insulation. Engineers are searching for new solutions to substitute the traditional system, as the rockwool presents health concerns. Acoustic metamaterials are among the candidates for new products in this field. This paper aims to verify the feasibility of an innovative ceiling design with enhanced Acoustic Black Holes (ABH). The proposed solution is compared with the traditional ones, using the Sound Reduction (R) as Key Performance Index (KPI). Traditional solutions are experimentally tested, and the data are used to assess an acoustic Finite Element Method (FEM) model, which is then used to simulate the acoustic properties of the proposed ceiling.

Numerical analysis of relative density effects on shallow TBM tunnel excavation: Ground behavior and principal strains at surface in greenfield conditions

Tunnel construction in urban areas may result in ground deformations that pose a risk to existing buildings and infrastructure; thus, accurate prediction of these induced ground deformations during the design phase is crucial. The paper focuses on the effects of sandy soil relative density on the ground deformations induced by tunnels excavated with Tunnel Boring Machines (TBMs). The study utilizes the Finite Element Method (FEM) and the NorSand model to simulate the behavior of a sandy ground. The validity of the FEM modeling approach is established by comparing predictions with results from six centrifuge tunnel tests from the literature. The centrifuge tests were performed on sand at different relative densities, tunnel diameters, and tunnel depths. The parameters for the NorSand model were determined based on laboratory tests. Only the state parameter was modified to achieve the desired relative density in the numerical simulations. The effects of relative density observed in centrifuge tests (Franza et al., 2019) have been numerically reproduced with no further adjustments of the model parameters. The rich outputs from the numerical models enabled an in-depth investigation of tunnel behavior, yielding new insights into how tunnels respond under varying relative densities, depths, and diameters. A comprehensive analysis of the induced ground deformations caused by shallow tunnels in sandy ground and the potential to damage buildings is included.

Восстановление лакового слоя изоляционных пальцев ТЭД с применением установки инфракрасного нагрева камерного типа

Purpose: based on an in-depth analysis of the causes of damage to the insulating fingers of traction motors of electric locomotives, it is necessary to develop a method for increasing their operational reliability. The most effective way to obtain the desired result is to use an improved technology for restoring the electrical insulating varnish layer of insulating fingers using thermoradiation heating. The implementation of a promising technology in depot conditions is possible with the use of a chamber-type infrared heating unit, the control unit of which contains the most optimal energy supply mode determined during experimental studies on a laboratory combined heating unit. Methods: the most significant results of the work were obtained thanks to experimental studies of the electrical and mechanical strength of the cured electrical insulating varnish layer of insulating fingers, in addition, in the process of determining the optimal energy supply mode, finite element modeling methods of thermal processes were used. Results: a design of a laboratory combined infrared heating unit has been developed, thanks to which the optimal drying mode of insulating fingers has been determined, embedded in the operation of an industrial chamber-type unit for drying a set of insulating fingers. Also, the dependence of the breakdown voltage and the hardness of the outer surface of the insulating finger, linking its mechanical and dielectric properties, was determined. Practical significance: the results of the work can be used to improve existing technologies for depot and factory repair of insulating fingers, in particular, to create a series of industrial infrared heating units in locomotive service depots. It is also worth noting that the obtained curve of the dependence of hardness and breakdown voltage, in the future, will allow assessing the electrical strength of insulating fingers indirectly by the hardness parameter of the outer varnish layer.

Stability impact on wind turbine blades trailing edge from bonding zone modelling methods

Abstract The trailing edge of wind turbine blade will undergo a large deformation under the action of load, resulting in a higher risk of damage and failure. The finite element analysis modeling method directly affects the simulation result, furthermore impacts the result of blade structure design. Therefore, it is necessary to find out a modeling method, which is capable to reflect the stability of bonding regions more accurately. This paper aims to discuss the influences of different finite element modeling methods on the buckling stability of blade trailing edge. The influences of shell element, tetrahedron element and hexahedron element on the blade stiffness are considered. The bonding region were simulated separately by combining shell element with bonding web, shell element with tetrahedron element and shell element with hexahedron. The influences of different bonding region modeling methods on the trailing edge buckling factor were analyzed by using the eigenvalue buckling analysis method of finite element. The simulation results provided data support for the future validation of the blade trailing edge bonding area modeling method. The results show that, the tetrahedral mesh provides a higher stiffness, followed by the hexahedral mesh, and the adhesive web form has the smallest stiffness. In order to simulate the more realistic stiffness of the adhesive area at the trailing edge of the blade, adhesive web plates can be built in the flange area of the blade root and the core material area of the trial adhesive mold; The direct bonding area can be simulated employing the hexahedron mesh; The tetrahedral mesh has high stiffness and is not suitable for modeling the adhesive area at the trailing edge. Blade simulation modeling can flexibly use different adhesive forms according to actual situations, ensuring the reliability of the simulation model.

Modeling electrical impedance in brain tissue with diffusion tensor imaging for functional neurosurgery applications

Objective.Decades ago, neurosurgeons used electrical impedance measurements in the brain for coarse intraoperative tissue differentiation. Over time, these techniques were largely replaced by more refined imaging and electrophysiological localization. Today, advanced methods of diffusion tensor imaging (DTI) and finite element method (FEM) modeling may permit non-invasive, high-resolution intracerebral impedance prediction. However, expectations for tissue-impedance relationships and experimentally verified parameters for impedance modeling in human brains are lacking. This study seeks to address this need.Approach.We used FEM to simulate high-resolution single- and dual-electrode impedance measurements along linear electrode trajectories through (1) canonical gray and white matter tissue models, and (2) selected anatomic structures within whole-brain patient DTI-based models. We then compared intraoperative impedance measurements taken at known locations along deep brain stimulation (DBS) surgical trajectories with model predictions to evaluate model accuracy and refine model parameters.Main results.In DTI-FEM models, single- and dual-electrode configurations performed similarly. While only dual-electrode configurations were sensitive to white matter fiber orientation, other influences on impedance, such as white matter density, enabled single-electrode impedance measurements to display significant spatial variation even within purely white matter structures. We compared 308 intraoperative single-electrode impedance measurements in five DBS patients to DTI-FEM predictions at one-to-one corresponding locations. After calibration of model coefficients to these data, predicted impedances reliably estimated intraoperative measurements in all patients (R=0.784±0.116,n=5). Through this study, we derived an updated value for the slope coefficient of the DTI conductance model published by Tuchet al,k=0.0649 S⋅smm-3 (originalk=0.844), for use specifically in humans at physiological frequencies.Significance.This is the first study to compare impedance estimates from imaging-based models of human brain tissue to experimental measurements at the same locationsin vivo. Accurate, non-invasive, imaging-based impedance prediction has numerous applications in functional neurosurgery, including tissue mapping, intraoperative electrode localization, and DBS.

Systematic simulation of tumor cell invasion and migration in response to time-varying rotating magnetic field.

Cancer invasion and migration play a pivotal role in tumor malignancy, which is a major cause of most cancer deaths. Rotating magnetic field (RMF), one of the typical dynamic magnetic fields, can exert substantial mechanical influence on cells. However, studying the effects of RMF on cell is challenging due to its complex parameters, such as variation of magnetic field intensity and direction. Here, we developed a systematic simulation method to explore the influence of RMF on tumor invasion and migration, including a finite element method (FEM) model and a cell-based hybrid numerical model. Coupling with the data of magnetic field from FEM, the cell-based hybrid numerical model was established to simulate the tumor cell invasion and migration. This model employed partial differential equations (PDEs) and finite difference method to depict cellular activities and solve these equations in a discrete system. PDEs were used to depict cell activities, and finite difference method was used to solve the equations in discrete system. As a result, this study provides valuable insights into the potential applications of RMF in tumor treatment, and a series of in vitro experiments were performed to verify the simulation results, demonstrating the model's reliability and its capacity to predict experimental outcomes and identify pertinent factors. Furthermore, these findings shed new light on the mechanical and chemical interplay between cells and the ECM, offering new insights and providing a novel foundation for both experimental and theoretical advancements in tumor treatment by using RMF.

Study on the dynamic response behaviour of the head cover-bolts-stay ring of a variable-speed pump-turbine

Abstract The vibration characteristics of the hydro-turbine’s head cover is a significant factor that affects the safety of the unit. This paper established the Finite Element Method (FEM) model for the head cover-bolts-stay ring system of a variable-speed pump-turbine, and the dynamic response behaviour of the system under pretension and hydraulic excitation conditions is analyzed. The results indicate that the maximum value of stress locates at the bolt root, which is 715.6MPa under pretension load and 678.7MPa under hydraulic excitation. The results presented in this paper offer valuable guidance for the safety and stability of the variable-speed pump-turbine.

Synergistic densification mechanism of irregular Ti powder during CIP: 3D MPFEM simulation with real-shape particles

Achieving high green density is essential for ensuring the mechanical properties of powder metallurgy workpieces. However, the densification behavior of irregular ductile powders remains unclear due to oversimplification in current numerical simulations. To address this, a three-dimensional multi-particle finite element method model incorporating realistic powder morphology, size distribution, and stacking structure is constructed. It is found that a pivotal motion-deformation synergistic stage exists between the conventional particle rearrangement and elastic–plastic deformation stages. In this stage, plastic deformation is driven by the spheroidization of coarse powders, whereas the resulting vacancies in the stacking structure facilitate slight particle motion. Thereafter, plastic deformation is dominated by the flattening of fine particles, and the pore-filling capacity decreases due to the reduction in non-contact surface area. This synergistic and complementary interaction between the spheroidization of coarse powders and the flattening of fine powders enhances mechanical interlocking and promotes micropore closure. As a result, the micropores exhibit a tendency of downsizing and homogenization, substantially boosting the potential for achieving full densification during sintering. Based on these findings, a method for determining the optimal forming pressure is proposed, considering the manufacturing costs of powder compacts and the characteristics of the micropores in both green and sintered bodies.

Finite Element Method Modelling for Extended Depth of Focus Acoustic Transducer

Abstract Extended depth of focus (DOF) with the high lateral resolution is the primary requirement of the transducer in scanning acoustic microscopy to generate high-resolution images of the 3-dimensional sample over a large depth. Traditionally, focused ultrasonic spherical transducers are used to tightly focus the acoustic waves generated from a piezoelectric material for a wide range of applications in industrial, medical, and other fields. Such transducers have a problem of narrow DOF which restricts the imaging range in depth. In the present work, we propose three different transducer designs such as single axicon, central flat axicon and double axicon, which enable the possibilities of high transverse resolution imaging over greater depths due to the significant increase in DOF. Finite element modeling (FEM) in COMSOL of a spherical, single axicon, central flat axicon, and double axicon transducer is systematically performed and compared in terms of transverse resolution, DOF, and acoustic pressure in the central lobe. In addition, the single axicon and double axicon transducer modeling are done for different apex angles. It is observed that the central flat axicon transducer allows customizable DOF and the double axicon transducer provides high lateral resolution and reduced pressure in the side lobes compared to a single axicon lens.