Finite Element Simulation Model Research Articles

Researching the force absorption system for the front of the passenger car to secure the driver

Protecting the safety of drivers in the bus is very important and necessary in front collisions. This research on the system shock absorber and absorption of force bus head in front collisions. This design will protect bus heads not violations in safe spaces and protect drivers in front collisions. The finite element model and safety analysis simulation of the system shock absorber and absorption of force by LS – DYNA and MADYMO software. The study’s results show shock absorber structure ensures durability. The head part index is down 35%. The neck part index is down 28%. Drivers are protected more safely. Injury values of driver satisfy safety ECE R94 standard in bus front collision. Keywords: ECE R94 standard, MADYMO software, LS - DYNA software, collision, injury.

Hydrodynamic resistance of pore–throat structures and its effect on shale oil apparent permeability

Oil transport is greatly affected by heterogeneous pore–throat structures present in shale. It is therefore very important to accurately characterize pore–throat structures. Additionally, it remains unclear how pore–throat structures affect oil transport capacity. In this paper, using finite element (FE) simulation and mathematical modeling, we calculated the hydrodynamic resistance for four pore–throat structure. In addition, the influence of pore throat structure on shale oil permeability is analyzed. According to the results, the hydrodynamic resistance of different pore throat structures can vary by 300%. The contribution of additional resistance caused by streamline bending is also in excess of 40%, even without slip length. Furthermore, Pore–throat structures can affect apparent permeability by more than 60% on the REV scale, and this influence increases with heterogeneity of pore size distribution, organic matter content, and organic matter number. Clearly, modeling shale oil flow requires consideration of porous–throat structure and additional resistance, otherwise oil recovery and flow capacity may be overestimated.

An active-bending sheltered pathway based on bamboo strips for indoor temporary applications: Design and construction

This study explores the feasibility of employing bamboo strips to create an innovative sheltered pathway designed for indoor temporary applications. The primary design objectives encompass the development of a lightweight structure to conserve materials, ease of installation, and the use of sustainable, environmentally friendly materials. Additionally, the study places a significant emphasis on creating a structural system that can be conveniently disassembled, occupying minimal space for easy transport. The research initiative commences by investigating the mechanical properties of bamboo strips under active bending conditions, employing both bending and cantilever tests to evaluate their performance. Subsequent numerical analyses are conducted using OpenSeesPy, utilizing elastic beam elements with a corotational geometric transformation to simulate the mechanical behavior of bamboo strips. These numerical simulations are then compared with experimental results, contributing to the validation of a mechanical model for the full active bending structure. This validated model is further employed to predict deformation status and stress distribution during the substantial deformations of bamboo strips. The Employing a Particle-Spring Assembly (PSA) model, the preliminary design seamlessly evolves from a 2D bamboo strips configuration to 3D structures, showcasing the final curved form inspired by the remarkable large deformation performance of bamboo strips. Finally, the validated model guides the design of three distinct prototypes of an active-bending sheltered pathway, progressively increasing in scale and complexity. The prototypes address challenges such as lateral stiffness and employ aluminum connections for enhanced performance. The stiffness of the final sheltered pathway prototype is simulated and validated through Finite Element Modeling (FEM) simulations in ABAQUS under diverse loading conditions. The ultimate prototype represents a full-scale module of the sheltered pathway, featuring a walkway, a shelter system constructed from transparent waterproof PVC fabric, and an LED strip-based lighting system. These initial designs and prototypes demonstrate promising performance and hold considerable potential for real-world applications, establishing them as a compelling subject of study.

Mitigating Crack Propagation in Hybrid Composites: An Experimental and Computational Study

The exceptional properties of carbon nanotubes (CNTs) make them ideal nanofillers for various composite materials. In carbon fiber-reinforced polymer (CFRP) composites. CNTs can be grown on the carbon fiber surface to act as a third interface between the fiber and the matrix. However, it was established that the uncontrolled random growth of CNTs could exacerbate delamination in composite structures. Thick nanofiller films could hinder the epoxy from seeping into the carbon fiber, resulting in insufficient interlaminar strength. Hence, the density and distribution of nanofillers play a crucial role in determining the hybrid composite fracture mechanisms. In this investigation, CNTs were grown using the low-temperature technique into specific patterns over carbon fibers to discern their derived composites’ fracture properties. The composite fracture energy release was probed using a double cantilever beam (DCB) test setup and digital image correlation (DIC) to monitor interlaminar crack propagation. A standard finite element simulation model based on the cohesive zone method (CZM) was also utilized to delineate fracture behaviors of the various composite configurations. Results conclude that a coarser pattern of CNT growth enhances resistance to crack propagation, thus improving the interlaminar fracture toughness of a composite structure.

Calculation model for critical depth of kinked dents on pipelines with internal pressure

Kinked dent is caused by the external force on the oil and gas pipeline, and its curvature is small, which seriously affects the operation safety of the pipeline. This paper focuses on the study of the critical depth of kinked dent for steel pipelines with internal pressure, to propose the safety evaluation criterion for pipelines with kinked dents. First, a full-scale hydraulic bursting test of a steel pipeline with kinked dents is designed, and the pressure-bearing capacity and the strain response law of the kinked dent in the test process are obtained. The results show that the pipeline does not fail at the kinked dent, and the kinked dent almost completely rebounds and has a certain pressure-bearing capacity. Then, a finite element simulation model of the pipeline with kinked dents is established, and the accuracy of the model is verified by comparing with the test. After that, the pressure-bearing failure mode and failure criterion of the pipeline with kinked dents are determined, the sensitive parameters affecting the failure are analyzed, and the effects of the parameters such as the depth and angle of the kinked dent, the diameter thickness ratio and yield ratio of the pipeline on the pressure-bearing capacity are obtained. Finally, based on many numerical simulation results, a calculation model for the critical depth is proposed as a safety evaluation criterion for the pressure-bearing failure of pipelines with kinked dents.

On the deformation of CRTS-Ⅲ ballastless track during the casting process of self-compacting concrete: Numerical simulations and random forest-based prediction models

CRTS (China railway track system)-Ⅲ slab track is a main structural type of ballastless track in Chinse high-speed railway (HSR), which requires precise positioning of prefabricated concrete track slabs. However, the cast-in-place process of the self-compacting concrete (SCC) filling layer induces a large deformation as the flowing SCC generates an up-lift force on the bottom of the track slab. Currently, the deformation mechanism and influencing factors of the track slab during the SCC casting process have not been thoroughly studied. In this work, a fluid-solid interaction finite element model (FEM) is created to calculate the upward deformation of the CRTS-Ⅲ track slab caused by the flowing SCC. The main influencing factors, including the SCC’s casting height and speed, SCC’s viscosity, constraint stiffness of the limiting beams, and vertical temperature gradient, have been systematically analyzed and discussed. The relationship between the influencing factors and the track slab’s deformation is obtained. Furthermore, machine learning prediction models using random forest algorithms are developed to evaluate the deformation and up-lift force. A dataset comprising 603 calculation cases obtained from FEM simulations is used to train the prediction models. The random forest-based models developed in this study give an accurate estimation of the deformation and up-lift force based on the SCC properties and construction parameters. In addition, the feature importance of each influencing factor is obtained and studied. The findings of this study can provide guidance for the control of the deformation in CRTS-Ⅲ track slab during the SCC construction process.

Design and Analysis of a Moment of Inertia Adjustment Device

The vibration frequency characteristics of a rotor system are directly related to its moment of inertia. In this paper, a moment of inertia adjustment device is proposed to adjust the frequency characteristics of a rotor system and better reduce vibration by changing the moment of inertia. First, a mathematical model of the moment of inertia and the temperature field are established. A finite element simulation model of the electromagnetic field of the electromagnetic control unit in the device is established. The influence of current and air gap on the electromagnetic forces is discussed. Then, the validity of the finite element simulation for the electromagnetic control unit is verified using experimental results. In addition, the variations in the displacement and force of the moving mass and the moment of inertia of the device with speed are analyzed. The results show that the proposed moment of inertia adjustment device can be used to significantly adjust the moment of inertia, which provides a reference for better controlling vibrations in rotor systems. Finally, a finite element simulation model for an electromagnetic field analysis of the electromagnetic control unit in the device is established. The results show that the maximum temperature of the electromagnetic control device is 332 K in 60 min, which is in accordance with the requirements.

Integration of Febio as an Instructional Tool in the Undergraduate Biomechanics Curriculum.

Computer simulations play an important role in a range of biomedical engineering applications. Thus, it is important that biomedical engineering students engage with modeling in their undergraduate education and establish an understanding of its practice. In addition, computational tools enhance active learning and complement standard pedagogical approaches to promote student understanding of course content. Herein, we describe the development and implementation of learning modules for computational modeling and simulation (CM&S) within an undergraduate biomechanics course. We developed four CM&S learning modules that targeted predefined course goals and learning outcomes within the febio studio software. For each module, students were guided through CM&S tutorials and tasked to construct and analyze more advanced models to assess learning and competency and evaluate module effectiveness. Results showed that students demonstrated an increased interest in CM&S through module progression and that modules promoted the understanding of course content. In addition, students exhibited increased understanding and competency in finite element model development and simulation software use. Lastly, it was evident that students recognized the importance of coupling theory, experiments, and modeling and understood the importance of CM&S in biomedical engineering and its broad application. Our findings suggest that integrating well-designed CM&S modules into undergraduate biomedical engineering education holds much promise in supporting student learning experiences and introducing students to modern engineering tools relevant to professional development.

3D printing finite element analysis of continuous fiber reinforced composite materials considering printing pressure

Continuous fiber reinforced thermoplastic composite (CFRTC) 3D printing technology, as one of the most remarkable manufacturing techniques, has made significant advancements in various fields, including aerospace and automobile manufacturing. However, there is a dearth of research on simulating the printing process of CFRTC considering printing pressure. This article presents a finite element model that incorporates printing pressure and employs element birth and death technology to simulate the printing process. An in-situ pressure monitoring platform is built to provide real data for simulation. By comparing the simulation results with the experimental results, it is found that the errors of the finite element model simulation results with pressure under different printing parameters are predominantly less than 5 %. Furthermore, the impact of printing temperature and speed on the deformation of the 3D printed CFRTC is analyzed. The deformation of the printed sample is more sensitive to the printing temperature than the printing speed. This study can provide important theoretical guidance for engineering applications.

Scaling laws of Space Solar Power Satellite concentrator unit distortion model obtained by performance-driven separate similitude analysis method

The distortion model may arise due to the inability to isometrically scale the thickness dimensions when utilizing similitude theory to develop scaling laws for large-scale concentrator units in the Space Solar Power Satellite. Previous works to address the distortion model neglect its negative impacts and persistent limits, resulting in insufficient prediction accuracy for prototype. To obtain scaling laws of the distortion model, this paper introduces a novel strategy called the performance-dominated separate similitude analysis, which significantly reduces the distortion model's negative impacts and persistent limits on similitude prediction. Firstly, performance parameters sensitive to the distortion model are generated by dimensional analysis and the governing equation method. Secondly, the distortion model is separated into two scaled models: complete and partial similitude, based on the sensitive performance parameters. Subsequently, the scaling laws of complete and partial similitude models are derived, respectively. Finally, the scaling laws of the distortion model are derived by combining the complete and partial similitude laws. The proposed method is validated through finite element model simulation for both the concentrator unit prototype and the distortion model. Results indicate that in the best case, the prediction error doesn't exceed 0.2 %, and the prediction accuracy can be improved by up to 87.34 % compared to the existing methods.

Construction and application of online parametric modeling platform for face milling cutters based on WebGL and Open CASCADE

The secondary development of traditional commercial CAD/CAE software has been widely used in the process of cutting tools design and optimization. However, limited by copyright and hardware configuration, the effect of this development is limited, and the secondary development can no longer meet the needs of rapid and accurate cutting tools design. With the rapid development of Internet, online cutting tools CAD software based on Web has become a new development direction with its characteristics of specialization and lightweight. In order to build an online cutting tools CAD software, an online parametric design platform for indexable face milling cutters is established based on Web development technology, Open CASCADE and Three.js. The platform can quickly generate a 3D basic model for NC machining programing and a 3D detailed model for finite element simulation of cutting process according to ISO 13399. Based on the built platform, the finite element simulation model of cutting process of indexable surface milling cutter is established. The establishment of the model can play an important role in improving the design efficiency and reducing the design cost for the optimal design of this kind of milling cutter.

Novel approach to the derivation of dam breach parameters in 2D hydrodynamic modeling of earthquake induced dam failures

Current methods of dam breach analyses adopt a deterministic approach. Applying these methods to Concrete Faced Rockfill Dams (CFRD) is fraught with huge levels of uncertainty, especially in the context of natural hazards. The frequency and magnitude of rainfall and earthquakes are higher in today's world. In the literature, the complete collapse of dams is modelled on dam breach parameters that define the dam break outflow but are not related to the return periods of natural hazards. As more new dams are constructed to control the floods in intra-plate seismic regions, this study presents a novel approach to the derivation of generalized dam break parameters for CFRD based on the structural analysis of Finite Element Model (FEM) simulations for peak ground accelerations corresponding to 475 and 2475 year return periods. Furthermore, the occurrence of rainfall and earthquake for different return periods are modelled using 2D hydrodynamic simulations. Results show the significance of generalized dam breach parameters for planning and managing CFRDs during earthquakes. The study emphasizes the utilization of structural analysis outputs for the hydraulic modeling of dam breaks, which will result in more specific and accurate dam break parameters. Additionally, the study has shown that the flood risk and the severity will increase with the intensity of earthquake and rainfall magnitudes. Disaster mitigation strategies can be optimized by considering the integrated occurrence of rainfall and earthquakes based on the probability of occurrence, demonstrated using a case-study dam. Another significant outcome of the study is the effect of soil saturation condition during a dam break, which reveals that areas within 40 km of the dam breach location might be worst affected.

The distribution law of shock wave pressure in typical trenches

Trenches, as important practical military facilities, have important theoretical and military value in evaluating the damage power of ammunition, operational application, and effective safety protection of personnel on the battlefield through the spatiotemporal evolution of explosive shock waves within them. At present, there is a lack of in-depth research on the distribution and impact of overpressure inside the trench. The paper constructed a typical finite element simulation model of a trench, numerically calculated the shock wave overpressure inside the trench and on the wall, analyzed the spatiotemporal distribution of shock wave pressure in various parts of the trench, conducted on-site explosion tests, and installed shock wave pressure sensor measurement points in the trench. The pressure time history curve was obtained, and verified and compared with the simulation calculation results. Research data shows that the peak overpressure of the shock wave in the trench increases sequentially from the front wall to the back wall. The peak overpressure of the shock wave at the front wall attenuates by 10 % to 20 % compared to the inside of the trench, and increases by 40 % to 60 % at the back wall; The peak overpressure in the trench exhibits a “V-shaped” distribution at different depths, decreasing first and then increasing as the depth increases. The maximum overpressure peak increases by 40 % to 50 % compared to the minimum; Based on simulation and measured data in the trench, as well as the distribution law of shock wave pressure, safety protection suggestions for on-site combat personnel in the trench are provided.

Research on the Magnetic Properties of High-Saturation Magnetically Induced Alloy Motors under Magnetocaloric Coupling.

In the face of the rapid development of the motor industry, some motors with traditional soft magnetic materials can no longer meet the needs of the market. Using new high-saturation magnetic density materials has become a new breakthrough to improve the torque density of motors. Fe-Co alloys (1J22) have high-saturation magnetic induction strength, which can effectively improve the motor's magnetic field strength and increase its torque density. At the same time, the temperature rise of the motor is also an important factor to consider in the motor design process. In particular, the change in core temperature caused by loss makes the coupling of the internal temperature field and the electromagnetic field of the motor more common. Therefore, it is necessary to test the temperature and magnetic properties of 1J22 together. In this paper, a coupling measurement device for magnetic properties of soft magnetic materials is built, and a 1J22 temperature field-electromagnetic field coupling experiment is completed. It is found that the maximum loss of 1J22 decreases by 4.44% with the increase in temperature; the maximum loss is 6.41% less than that of traditional silicon steel. Finally, a finite element simulation model is built to simulate the actual working conditions of the motor, and it is verified that the magnetic properties of the material at high temperature will have a certain impact on the performance of the motor.

Guided Wave-Based Early-Stage Debonding Detection and Assessment in Stiffened Panel Using Machine Learning With Deep Auto-Encoded Features

Abstract Debonding between stiffener and base plate is a very common type of damage in stiffened panels. Numerous efforts have been made for debonding assessment in the stiffened panel structure using guided wave-based techniques. However, these studies are limited to the detection of through-the-flange-width debonding (i.e., full debonding). This paper attempts to develop a methodology for the detection and assessment of early-stage debonding (i.e., partial debonding) in the stiffened panel using machine learning (ML) algorithms. An experimentally validated finite element (FE) simulation model is used to create an initial guided wave dataset containing several debonding scenarios. This dataset is processed through a data augmentation process, followed by feature extraction involving higher harmonics of guided waves. Thereafter, the extracted feature is compressed using a deep autoencoder model. The compressed feature is used for hyperparameter tuning, training, and testing of several supervised ML algorithms, and their performance in the identification of debonding zone and prediction of its size is analyzed. Finally, the trained ML algorithms are tested with experimental data showing that the ML algorithms closely predict the zones of debonding and their sizes. The proposed methodology is an advancement in debonding assessment, specifically addressing early-stage debonding in stiffened panels.

Finite Element Simulation Parameter Calibration and Verification for Stem Cutting of Hydroponic Chinese Kale

The finite element simulation is a valid way for the rapid development of the root-cutting mechanism for hydroponic Chinese kale. The stem of the hydroponic Chinese kale was simplified as a transverse isotropic elastic body, and axial compression, three-point bending, and shear tests were performed. The ANSYS/LS-DYNA19.2 software was adopted for stem shear simulation, and the regression equation of the maximum simulated shear force was established. The optimized mechanical parameters were determined by minimizing the deviation between the maximum shear force obtained from the simulation and test. The three-dimensional scanning method was employed to establish the geometric model of the hydroponic Chinese kale stem. The cutting finite element simulation model and test platform were constructed. Displacement, deformation, and force measured from simulation and test were compared. Through measurement and simulation calibration, an axial elastic modulus of 6.22 MPa, axial Poisson’s ratio of 0.46, radial elastic modulus of 3.56 MPa, radial Poisson’s ratio of 0.44, radial shear modulus of 0.8 MPa, and a failure strain of 0.08 were determined. During the cutting simulation and test, the resulting maximum displacement deviations of the marking points on the end of the stem were 0.68 mm along the X-axis and 2.83 mm along the Y-axis, while the maximum deviations of the cutting and clamping force were 0.49 N and 0.77 N, respectively. The deformation and force variation laws of the kale stem in the cutting simulation and test process were basically consistent. It showed that the mechanical parameters calibrated by the simulation were accurate and effective, and the stem cutting simulation results with the finite element method were in good agreement with that of the cutting test. The study provided a reference for the rapid optimization design of the root-cutting mechanism for hydroponic Chinese kale harvest.

Temperature Rising Analysis of Dry-type Reactor Based on Multi-physical Coupled-field Method

To study the temperature-rising characteristics of the windings of the dry-type reactor, a three-dimensional (3D) finite element (FE) simulation model of electromagnetic-fluid-temperature coupling of the reactor is constructed by using the method of the multi-physical field coupled modeling. Firstly, based on the magnetic-circuit coupled theory, the electromagnetic analytical model of the reactor is created and analyzed, and the heat density per unit volume of the reactor is obtained. Then, based on the heat transfer principle of fluid-temperature coupling, taking the heat density per unit volume of the reactor as the heat source, the 3D model of the reactor with fluid-temperature coupling is analyzed by the finite volume method, and the distribution of the internal temperature of the reactor is obtained. From the simulation results of the reactor, the temperature in the upper region is higher than that in the lower region, and the temperature of both sides is lower than that of the middle region. The change regulations of the temperatures in the different encapsulations are basically the same. The temperature gradually increases from the bottom to the top, and the maximum temperature locates at approximately 90% of the axial height of the reactor. The research results provide reference for structure modification, temperature-rising monitoring and overheating fault diagnosis of the reactor.

Effect of temperature on the ductile-to-brittle transition in laser-assisted mechanical ruling of silicon

This paper introduces an innovative hybrid processing method that combines in-situ laser assisted with mechanical ruling. The innovative diamond ruling tool can facilitate laser incidence from both the A and B faces. Additionally, this paper establishes a thermal-mechanical coupled finite element simulation model for in-situ laser-assisted mechanical ruling of single-crystal silicon with varying cutting depths. It aims to analyze the material removal process and the effect of temperature on the ductile-to-brittle transition. In the process, an in-situ laser assisted mechanical ruling setup is designed to investigate the impact of different laser powers on the ductile-to-brittle transition. The experimental results align with the simulation outcomes. When the laser power was set to 30W, the critical ductile-to-brittle transition depth reached 320.69 nm, successfully suppressing brittle fracture, validating that the proposed in-situ laser assisted mechanical ruling hybrid processing method can enhance the critical depth of ductile-to-brittle transition and improve the surface quality of microgrooves.

Radiated emission from DC bus loop of AC induction motor inverter FEM based and experimental evaluation

The paper describes practical method how to analyze locally radiated magnetic field to improve the geometry of printed circuit board (PCB) or busbar structure, select better control method and design electromagnetic interference (EMI) filter. Experimental prototype of three-phase induction motor variable frequency drive has been created and controlled by microcontroller with sinusoidal, namely pulse with modulation (PWM) method. Three-dimensional finite element model simulation of DC bus structure has been created and results has been obtained. Electromagnetic field was measured, practically and results compared with simulation-based ones. Simulation based and experimental results matches thus allowing to conclude method usefulness for cost effective way to test different geometries of DC bus, different modulation methods, EMI filters for variable frequency drive, and other power electronics converters.

Magnetic-Control Variable Stiffness and Damping Tail Support for a Wind-Tunnel Aircraft Model

To suppress random vibration of aircraft models during wind tunnel tests, a novel magnetorheological elastomer (MRE)-based device with variable stiffness and variable damping (VSVD) is proposed, which is installed on the tail support system. Firstly, the dynamic characteristics of the tail support system are established using finite element model simulation to obtain the vibration mode and stress distribution. Next, the vibration reduction mechanism of the MRE-based tail support system is analyzed by solving a finite element model. Then, the magnetic-controlled VSVD device with an annular sandwich structure is proposed, and the decisive rheology material and structural parameters in relation to the tail support system’s dynamics are determined. Subsequently, the magnetically generated element with multicoils is designed to guarantee a large enough magnetic field, and the optimal structure parameters are obtained. Finally, random wind flow experiments in the wind tunnel and frequency sweep tests in the ground laboratory for the tail support system equipped on the VSVD device are conducted to verify the effectiveness of the proposed device, respectively. The results under 15–200 Hz random excitation indicate the root mean square of acceleration at the centroid of the aircraft model with the VSVD device can be decreased by 46.8% compared to the system without the VSVD device.