Finite Element Simulation Technology Research Articles

Study on fracture failure behaviour of sapphire transparent window under ultra-high hydrostatic pressure

ABSTRACT Accurately predicting the fracture damage behaviour of light transmission windows is crucial in the design of deep-sea optoelectronic devices. This study proposes a simulation model based on the exponential cohesive zone law to predict the fracture failure of sapphire transparent windows (STW) under multi-dimensional load conditions. By utilising finite element simulation technology, the model accurately determine the fracture damage morphology and failure location of STW in different assembly structure schemes under a hydrostatic pressure of 127 MPa. These simulation results are then effectively validated through full sea depth pressure test experiments. Furthermore, by analyzing the simulation data, this study uncovers the internal mechanism of the fracture damage process of STW and presents a method to predict the fracture damage of STW. This research enhances the understanding of fracture behaviour in light transmission windows and offers valuable insights for the design and development of deep-sea optoelectronic devices.

Cutting Finite Element Simulation of Quenched Steel GCr15 Based on ABAQUS

Background:: The substantial cutting force and elevated cutting temperature during the machining of hardened steel GCr15 exacerbate tool wear. Objective:: In this study, the influence of cutting parameters on cutting force and cutting temperature in the process of hard-cutting GCr15 was studied, the cutting parameters were optimized, and the cutting force and cutting temperature were predicted. Methods:: The cutting simulation model was constructed using ABAQUS software, and the cutting force and cutting temperature were investigated under various cutting parameters through range analysis, variance analysis, and signal-to-noise ratio transformation analysis. Results:: The simulation and experimental results demonstrated that the cutting force could be optimized by utilizing cutting speed vc=140m/min, feed rate f=0.1mm/r, and cutting depth ap=0.1mm. Under these conditions, the cutting force in the x-direction was measured as 78.560N, while the cutting force in the y-direction was 32.423N. Moreover, for achieving the optimal cutting temperature, the recommended cutting parameters were cutting speed vc=120m/min, feed rate f=0.1mm/r, and cutting depth ap=0.4mm. Conclusion:: Compared to the conventional analytical method, which is burdened with high costs and low efficiency, the patent leverages finite element simulation technology to replicate the hardcutting process and its underlying cutting mechanism. This innovation simplifies the otherwise complex and laborious experimental and measurement procedures. By studying cutting force and cutting temperature, the optimization of cutting parameters can be achieved, thus offering valuable theoretical insights for practical production.

Optimal Design of a Six-Dimensional Force Sensor with Three-Beam Structure

A six-dimensional force sensor with a three-beam structure was designed, and its strain and stress distribution under various load conditions were analyzed based on finite element simulation technology. According to the strain distribution, the Wheatstone bridge scheme of the sensor is designed, and the output voltage and sensitivity formulas in each direction are deduced. The optimal patch location was determined according to the strain distribution on the centerline of the strain beam. Finally, the size parameters of the elastic body were optimized based on the response surface method and multiobjective genetic algorithm, which greatly improved the sensitivity of the sensor in all directions. It can provide a useful guidance for the optimal design of the six-dimensional force sensor with a three-beam structure.

Investigation on Dynamic Impact Mechanism of Single Crystal Sapphire 3D Model Based on Cohesive Zone Law

AbstractBased on mesh reconstruction technology, a 3D solid model of single crystal sapphire (SCS) with global embedded cohesive element is established in this study. Using exponential cohesive zone law (CZL), the anisotropy of SCS can be effectively characterized by assigning the mechanical properties of matrix element and cohesive element. Taking the C‐plane SCS model as the research object, the whole process of dynamic evolution of cracks in the model under high‐speed surface impact and high concentrated stress impact is reproduced by finite element simulation technology. The simulation is compared with the experimental results from the aspects of crack initiation morphology, crack propagation path, sample fragmentation form, and mechanical response curve. The dynamic compressive strength reaches 1630.3 MPa with the impact velocity of 30 m s–1 in surface impact type. The initial maximum loading force reaches 320 N when the impact velocity is 8.35 m s–1 in the indentation impact type. In addition, by combining the simulation results, this study clarifies the mechanism of strain rate effect exhibited by SCS from the perspective of stress–strain data and crack evolution characteristics. Therefore, the model established in this study can effectively reflect the mechanical behavior of SCS under impact load.

Effect of Coated Composite Micro–Texture Tool on Cutting Shape and Cutting Force during Aluminum Alloy Cutting

Aluminum alloy materials are very difficult to break in the processing process; chip accumulation leads to poor processing stability. In this paper, a coated composite micro–textured tool is presented. The influence of coated composite micro–textured tool on chip shape and cutting force under the same cutting parameters is studied. Firstly, the combination of cutting force and cutting temperature is optimized based on cutting test. Secondly, combined with the finite element simulation technology, three kinds of composite micro–texture tools are tested to determine the same cutting parameters, tools and workpiece materials, and optimize the composite micro–texture combination from the angle of chip shape, cutting temperature and cutting force. Finally, on the basis of optimizing the microstructure combination, the optimization of the cutting performance of aluminum alloy by coating material is studied. It was found that the chip was more easily broken in the composite microstructure when two tools were used. The cutting force decreased by 25% and the cutting temperature decreased by 9.09% compared with the non–micro–texture tools. The cutting temperature and cutting force decreased by 3% and 4.99% compared with those of uncoated composite microstructure.

Study on the Influence of Delamination Damage on the Processing Quality of Composite Laminates

Internal delamination damage in composite connection structures can occur in the process of the overloading of a high-speed bearing, with alternating force loads, high or low temperatures, and the humid or hot environment loads. Mechanical drilling and riveting are usually used at the delamination position and outside its envelope, to inhibit delamination expansion. However, delamination damage can change the structural stress state of the original structure. It is difficult to achieve a better inhibition effect using conventional drilling mechanisms and process methods with intact composite panels, and new damage forms can even be introduced into the drilling process due to unreasonable parameter settings. Therefore, this paper combined finite element simulation technology and experimental processing technology, to analyze the influence of different delamination dimensions and positions on processing quality. The results showed that the feed speed and rotating speed had significant effects on the axial force of composite laminates. In particular, in the case of a low speed and high feed, the axial force will increase significantly.

Fabrication technology and performance tests for optical fiber-encapsulated, high-temperature superconducting tapes

Realizing fast and accurate quench detection is a great challenge for the application of long high-temperature superconducting (HTS) conductors. The combination of a distributed temperature sensing (DTS) system and optical fiber-encapsulated HTS (OFE-HTS) tape may become a promising approach to solve this problem. As a recently proposed composite HTS tape, its properties have not been studied systematically yet. Therefore, in this study, the electromagnetic and thermal behaviors of the OFE-HTS and traditional HTS tapes are compared by finite element simulation technology. The simulation results predict that the embedded optical fibers will hardly change the original electric, magnetic and thermal characteristics of the HTS tapes. In addition, a detailed fabrication method for OFE-HTS tape is introduced, and the composite tape performances including structural integrity, critical current uniformity, anti-bending/tensile force and quench response are tested seriatim. According to the microscope and x-ray detection results, the optical fibers are fully embedded in the OFE-HTS tape through the presented fabrication process. The critical current uniformity test results show the average critical current of the prepared 76 m long OFE-HTS tape is about 520 A, and the uniformity variation is about ±4%. The prepared OFE-HTS and traditional tapes have similar anti-bending/tensile properties. Finally, to check the effectiveness of the embedded optical fiber for quench detection, the fabricated OFE-HTS coil is tested. The quench detection results show that the temperatures in the same area measured by the optimized DTS system and a thermocouple are similar. Moreover, the temperature response ability of the optimized DTS system is better than that of the thermocouples, and the optimized DTS system is able to effectively avoid environmental electromagnetic field interference.

Simulation analysis of titanium alloy micro-drilling based on thermo-mechanical coupling

With the increasing demand for high precision micro parts in machining field, the development of micro hole drilling technology, especially the finite element simulation technology is rapidly promoted. However, there are many limitations in the simulation of micro-drilling, such as element size, computational efficiency, chip forming, etc. In the present work, a finite element software, Abaqus has been used to simulate the thermal-mechanical coupling micro-drilling process of titanium alloy material, and the key technologies, such as twist bit modeling, material constitutive model, chip separation criterion and element division, were investigated. Through simulation, it was found that with the increase of rotational speed and the decrease of feed speed, chip shape gradually fragmented, in addition, thrust force and torque diminished. Since chip shape, thrust force and torque are important factors affecting drilling quality and tool life, the work could offer important guiding significance for cutting parameter optimization.

Biomechanical study of anterior and posterior pelvic rings using pedicle screw fixation for Tile C1 pelvic fractures: Finite element analysis.

The purpose of this study was to analyse the biomechanical characteristics of pedicle screws with different placement methods and diameters in the treatment of Tile C1 pelvic fractures by finite element simulation technology and to compare them with the plate fixation model to verify the effectiveness of pedicle screw fixation. A three-dimensional digital model of a normal pelvis was obtained using computed tomography images. A finite element model of a normal pelvis containing major ligaments was built and validated (Model 1). Based on the verified normal pelvis finite element model, a Tile C1 pelvic fracture model was established (Model 2), and then a plate fixation model (Model 3) and a pedicle screw fixation model with different screw placement methods and diameters were established (Models 4-15). For all pelvic fracture fixation models, a vertical load of 500 N was applied on the upper surface of the sacrum to test the displacement and stress distribution of the pelvis in the standing state with both legs. The finite element simulation results showed the maximum displacement of Model 1 and Models 3-15 to be less than 1 mm. The overall maximum displacement of Models 4-15 was slightly larger than that of Model 3 (the maximum difference was 177.91×10-3 mm), but the maximum displacement of iliac bone and internal fixation in Models 4-15 was smaller than that of Model 3. The overall maximum stress (maximum stress of the ilium) and maximum stress of internal fixation in Models 4-15 were less than those in Model 3. The maximum displacement difference and maximum stress difference at the fracture of the pubic ramus between each fixed model were less than 0.01 mm and 1 MPa, respectively. The greater the diameter and number of pedicle screws were, the smaller the maximum displacement and stress of the pelvic fracture models were.The maximum displacement and stress of the pelvic fracture models of the screws placed on the injured side of the pubic region were smaller than the screws on the healthy side. Both the anterior and posterior pelvic rings are fixed with a pedicle screw rod system for treatment of Tile C1 pelvic fractures, which can obtain sufficient biomechanical stability and can be used as a suitable alternative to other implants.The greater the diameter and number of pedicle screws were, the greater the pelvic stability was, and the greater was the stability of the screws placed on the injured side of the pubic region than the screws on the healthy side.

Three-Dimensional CFD Modeling on the Thermal Characteristics of Buried Oil Pipeline Involving the Heat Transfer of Wax Layer

It is common to have a wax layer on the inner wall of waxy crude oil pipeline. However, the study of the wax layer on the heat transfer of buried pipeline systems is inadequate due to its instability of composition and properties; it may lead to the inaccurate prediction of the pipeline temperature field. Based on the finite element simulation technology, a three-dimensional heat transfer model of buried crude oil pipeline involving wax layer was proposed and solved. The thermal effect of the wax layer on pipeline system was analyzed quantitatively. Numerical results show that the average deviation of soil temperature near the pipeline reach 1.42 K when there is a 4 mm wax layer. Among different thermal conductivity models of heterogeneous materials, the EMT model plays best in predicting the conductivity of a waxy layer. By setting different working conditions, the influence mechanisms of several thermal influencing factors are discussed. The results show that the thermal influence range of heated pipe is positively associated with oil temperature and velocity. The core thermal response zone is about 12 m along the X-axis. Beyond 8 m depth from ground surface, the temperature fluctuation of soil is almost unaffected by the oil pipeline.

Application of Artificial Intelligence Extrusion Die Model Based on Finite Element Simulation in Decorative Material Aluminum Alloy

At this stage, the varieties and specifications of aluminum profiles continue to increase, and the scope of application continues to expand. The extrusion forming process is the key technology to realize the production of aluminum profiles, and its technological level determines the quality of the profile products and the service life of the mold. However, in actual production, the quality of the die is difficult to guarantee, and it takes multiple die trials and die repairs to produce qualified products. The numerical simulation technology is used to simulate the actual extrusion process, which can track and describe the flow behavior of the metal in real time, reveal the real flow law of the metal, predict the possible defects of the profile during the extrusion process, and adjust the mold structure and process parameters in time. It can not only improve the quality of extruded profiles, but also reduce production costs and shorten the mold production cycle. Based on this, this paper established an extrusion die optimization design model integrating finite element simulation technology and artificial intelligence algorithm. The prediction models were established with the mean square deviation of the section velocity, the maximum extrusion force and the maximum temperature of the section, respectively, and the optimal design of the structure was realized by using the particle swarm algorithm. The experimental results show that the model in this paper can realize the function well, which verifies the validity of the model.

Bolt Coupling Structure of Contact Stress and the Influence Factors of Joint Stiffness Based on Finite Element Method

Considering the nonlinear factors, such as the contact and friction between plates as well as bolt and plates, bolt preload, etc.Three-dimensional finite element model of a bolted structure was constructed. Based on the elastic strain theory and finite element simulation technology, the contact stress and joint surface stiffness of bolt connection structure are studied. Assuming that the compressive stress of the connected parts is distributed in a cone, the cubic expression of the contact stress distribution is established; Through a large number of simulation experiments, the empirical formulas for calculating the stiffness of the connected parts are given, and compared with several main theoretical analysis methods, the validity and feasibility of the formulas are verified.Three mathematical expressions of contact stress was deduced, which was based on the assumption that stress distribution in a circular cone. Compared with the finite element analysis, the corresponding error is within 5.8%; The influence to contact stress between connected components was analyzed with different thickness of the connected component, the diameter of nut. the experience formula of the connection stiffness was got, compared with the finite element analysis, the error of obtained member stiffness less than 14.3%.

Analysis of Crucial Factors Affecting Contact Force of PCB Spring Terminals Based on Simulation and Rank Correlation

A PCB spring terminal is a common type of connector found on the printed circuit board of electronic devices. Contact force is a crucial performance metric of this component that directly affects the product’s dependability. In actual production, the contact force is unstable, and the influencing factors are unknown, whereas conventional experimental research is restricted to costly and error-prone trial-and-error procedures. In this study, finite element simulation technology and Spearman rank correlation analysis are combined to determine the crucial factors controlling the contact force of the PCB spring terminals in the structural design parameters and the plating related parameters. The validity of the results is confirmed by the measured data. The results indicate that the thickness of the spring terminal is the most significant factor in controlling the contact force. According to the conclusion, the company has re-established the inspection standard and resolved production problems. This case shows that the combination of finite element simulation and correlation analysis can be used to find the most important design parameters of such components quickly, accurately, and cheaply.

Building Structure Simulation System Based on BIM and Computer Model

This paper does some research and discussion on the finite element analysis of a building structure, especially the computer graphics simulation method in building structure simulation. Moreover, with the support of BIM technology and computer finite element simulation technology, this paper constructs a building structure simulation system and analyzes the building structure simulation system based on actual conditions such as building structure and stress load. In addition, this paper improves the traditional structural analysis algorithm and designs experiments to evaluate the effect of the method proposed in this paper and analyze the data in the form of simulation to compare the validity of the test results. Finally, an experiment is designed to evaluate the data processing capability of the test system in this paper. The experimental analysis results verify the effectiveness of the method in this paper, which can provide relevant theoretical references for subsequent building structure simulation.

Mechanical Properties of SiC Whisker-Reinforced Aluminum Matrix Composite Wheel

Carbon fiber composite has advantages such as high specific heat capacity, low coefficient of thermal expansion and low elastic modulus. The SiC whisker-reinforced aluminum (SiCw-Al) matrix composite wheel has been developed to address the thermal fatigue failure of wheels caused by the braking heat. This paper studied the thermal cycle characteristics, crack propagation and fracture mechanism of SiCw-Al matrix composite wheel. Using finite element simulation technology, it compared the fatigue life of both the SiCw-Al matrix composite wheel and the traditional steel wheel. According to the findings, during braking, the wheel made of SiCw-Al matrix composites has 20.1% lower maximum temperature than the ordinary steel wheel; Its maximum safety factor (yield strength/maximum stress) has increased by 1.08, and its fatigue life is significantly longer. The SiCw-Al matrix composites show excellent mechanical properties and is thus widely used.

Thermal performance simulation of nano material modified fly ash light energy-saving wallboard in assembly building

Nowadays, China's urbanized buildings are prominent, and the building area continues to grow. The study of keeping the temperature of the building walls constant has become an indispensable key standard for building energy conservation. The purpose of this paper is to simulate and study the thermal energy performance of nanomaterial modified fly ash lightweight energy-saving model in prefabricated buildings. In this paper, in the selection of nanomaterial modified fly ash technology, the finite element simulation technology is adopted to study the thermal insulation effect of nanomaterial modified fly ash in building materials, and it also plays a guiding role in the actual work. In the experiment of improving fly ash lightweight and energy-saving wallboard with nanomaterials, we set up two groups of controlled experiments, namely modifying fly ash with traditional materials and modifying fly ash with nanomaterials. By comparing the heat preservation and heat insulation performance of modified energy-saving wall panels in prefabricated buildings. The results show that the nano-material modified fly ash foamed concrete, as 140 mm thick fabricated wall panel, has a good inhibitory effect on temperature transfer in the simulation of heat transfer. Under the condition of air-conditioning heating in winter and cooling in summer, the temperature difference between the inner surface temperature of the wall envelope (16.32 °C in winter and 23.25 °C in summer) and the indoor temperature (15 °C in winter and 23 °C in summer) is less than 3 °C. Therefore, the flyash lightweight energy-saving wallboard modified by nanomaterials can play a role in heat insulation and show good heat insulation characteristics in prefabricated buildings.

Dynamic numerical simulation analysis of a large caliber artillery projectile extrusion process

Taking a large-caliber gun as the research object, a projectile and gun coupling finite element numerical simulation model during the extrusion process is established according to the finite element simulation technology. The dynamic simulation of the extrusion process is carried out by using ABAQUS/EXPLAICT solver, and the stress variation law of the projectile belt during the groove and the barrel during the extrusion process is obtained. In the post-processing module of the finite element software, the data of displacement, velocity and acceleration at the center of mass of the projectile in the extrusion process are extracted, and the motion law of the projectile in the extrusion process is analyzed, which provides some reference value for the study of the extrusion process of large caliber artillery projectile.

Effects of parameters selection with transcranial direct current stimulation based on real head model

Transcranial direct current stimulation (tDCS) is a brain stimulation intervention technique, which has the problem of different criteria for the selection of stimulation parameters. In this study, a four-layer real head model was constructed. Based on this model, the changes of the electric field distribution in the brain with the current intensity, electrode shape, electrode area and electrode spacing were analyzed by using finite element simulation technology, and then the optimal scheme of electrical stimulation parameters was discussed. The results showed that the effective stimulation region decreased and the focusing ability increased with the increase of current intensity. The normal current density of the quadrilateral electrode was obviously larger than that of the circular electrode, which indicated that the quadrilateral electrode was more conducive to current stimulation of neurons. Moreover, the effective stimulation region of the quadrilateral electrode was more concentrated and the focusing ability was stronger. The focusing ability decreased with the increase of electrode area. Specifically, the focusing tended to increase first and then decrease with the increase of electrode spacing and the optimal electrode spacing was 64.0-67.2 mm. These results could provide some basis for the selection of electrical stimulation parameters.

Unified correlation of constraints with crack arrest toughness for high-grade pipeline steel

There is much controversy surrounding using laboratory specimens to predict the fracture behavior of high-grade pipeline steel due to their different constraints. Since there is a lack of unified parameters to quantitatively characterize the constraint effects, a model for the transformation of crack arrest toughness between different specimens and pipes has not been formed. In order to solve this problem, the evolution law of the plastic zone of the crack tip with the crack tip opening degree under different in-plane and out-of-plane constraints is explored using the finite element simulation technology. On this basis, a constraint parameter η which is based on the area APEEQ surrounded by the isoline of equivalent plastic strain εp at the crack tip is proposed. The feasibility of this parameter to characterize both in-plane and out-of-plane constraints is discussed, and a quantitative correlation model between it and the crack arrest toughness, critical crack tip opening angle (CTOAC), is established. The results show that the proposed parameter can be used to characterize the overall constraints caused by different specimens with different loading forms and geometries. The normalized arrest toughness, CTOAC/CTOAref, has a linear relationship with η1/2, and the correlation line is only related to the material. The quantitative correlation model has universal applicability for different specimens and is expected to predict the transformation of crack arrest toughness between laboratory specimens and pipelines.

Research on Finite Element Method of Hot Forming of High Strength Steel Sheet

The finite element simulation technology can provide strong support for the optimization of processing technology and the treatment of detailed problems in the processing process. Two finite element methods applied to hot forming of high-strength steel plates are introduced, namely the incremental method and the deformation method. Two methods are used for simulation calculations. The finite element simulation based on incremental theory has high accuracy and requires more complete mold and process information. It is mainly used in the middle and late stages of product and mold design. And the finite element simulation based on deformation theory have fast calculation speeds and are mainly used in the early stages of product and mold design. Both types of methods have high practical value.