Finite Element Analysis Software Research Articles

Multi‐Objective Optimization Design of Vacuum Interrupter Structure Based on Improved Artificial Jellyfish Search Algorithm

An improved multi‐objective optimization method based on artificial jellyfish search algorithm is proposed to solve the multivariable and multi‐objective optimization problem of vacuum interrupter with mutual coupling of structural parameters and mutual restriction of performance indexes. The finite element model of 40.5 kV/31.5kA vacuum interrupter is established. The structural parameters of seven important parts such as contact diameter and contact sheet thickness in vacuum interrupter are taken as optimization variables. The optimization objective is to maximize the longitudinal magnetic field strength and minimize the conductor resistance at the peak breaking short‐circuit current of vacuum interrupter. The artificial jellyfish search algorithm is improved on the population position initialization strategy and the population mutation cross‐update strategy. The Pareto front solution of the structural parameters of the vacuum interrupter is obtained by the joint simulation of finite element analysis and numerical calculation software. Finally, the multi‐parameter and multi‐objective optimization design of vacuum interrupter structure is realized. The comprehensive performance index is introduced into the optimal parameter group of jellyfish on the Pareto front. Under the constraint of weight variables, the optimal structural parameters of contact system are obtained. The axial magnetic induction intensity of the optimized vacuum interrupter contact is increased by 13.2%, and the conductor resistance is reduced by 25.4%. The comprehensive performance of vacuum interrupter is improved by 17.8%, and the stability and reliability of the power system are further improved. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

The response of diagrid structures to fire

The diagrid structural system has seen significant uptake in medium to high rise buildings because of the architectural and resource advantages that it provides. These arise mainly as a result of flexibility in the topology that this particular structural solution provides. However, as a result of the way in which diagrids carry both horizontal and vertical loading, the diagrid structure itself may be susceptible to fire in ways which are not immediately obvious on the basis of our understanding of more traditional rectilinear construction forms. This study addresses this to improve our understanding of diagrid structures' response to fire. A comprehensive structural analysis on 45 fire load cases is conducted, considering different fire locations and sizes, using parametric design tools and finite element analysis software. The results provide valuable insights into the load redistribution and collapse mechanisms of diagrid structures in fire conditions.

Notch Fatigue Life Research Based on Critical Distance Theory

Orthotropic anisotropic steel bridge panels are widely used in civil engineering due to their advantages of light deadweight, high ultimate bearing capacity, and wide range of applications. However, their fatigue problem is serious, and the fatigue-resistant design of the steel box girder diaphragm curved cutout is still difficult. In order to effectively predict the fatigue life of this typical fatigue-susceptible detail, a fatigue test of the specimen with curved notched segments of the diaphragm was carried out. ABAQUS 2016 version finite element analysis software was used to establish three kinds of finite element simplified models of the fatigue specimens with curved notches, and the laws of the influence of different notch radii on the fatigue life of the specimens were studied. Through the finite element solution of the three arc notch specimen models with different radii under the tensile load of 50 kN their respective principal stress distributions were obtained. The critical distance theory was introduced to analyze the characteristic stresses in the stress concentration area of the arc notch, and the point method and line method were used to calculate the characteristic stresses. The fatigue life prediction models of three kinds of notched components were established by combining the material fatigue limit and FE-safe life results. The results show that the point method is more conservative than the line method; no matter if the point method or the line method is used, the characteristic stress and the notch radius are inversely proportional to each other, and it is beneficial for the fatigue life of the structure to appropriately increase the notch radius. The fatigue prediction model of steel box girder diaphragms with curved notches based on the critical distance theory is of high accuracy, which is basically consistent with the test results, verifying the feasibility of the critical distance theory in the fatigue life prediction of notched specimens, and providing a reference for the fatigue life assessment of similar steel structures.

Experimental and Numerical Investigation of Flexural Properties of Solid Wood Materials Reinforced with Various FRP

Wood material is destroyed over time by biotic and abiotic factors. Many of the historical buildings are made of wooden materials and these materials can degrade over time with the effect of environmental conditions. In order to ensure the sustainability of these buildings with historical value, they need to be repaired and strengthened over time. In this study, 20x20x360 mm wood specimens of Ash tree species were strengthened with carbon, basalt and glass based FRP materials. The flexural properties of the reference sample without wrapping and the samples reinforced with carbon, basalt and glass based FRP material were examined. For this purpose, at first three-point bending test has been performed, and then obtained results are compared with the numerical ones found from finite element analysis software ANSYS. As result, a good agreement has been found between experimental and numerical results. As a result of the flexural tests, the load-displacement curves, values of flexural strength and values of modulus of elasticity the samples were determined. In this study, it was determined that the highest load carrying capacity value belongs to the sample reinforced with carbon-based FRP polymers.

Prediction of fatigue life of mistuned steam turbine blades subjected to variations in blade geometry

There is a large number of power stations suffering from fatigue failures of the steam turbine blades. The steam turbine blades are also subjected to steam flow bending, centrifugal loading, vibration response, and structural mistuning. These mentioned factors significantly contribute to the fatigue failure of the steam turbine blades. Low-Pressure (LP) steam turbines experience premature blade and disk failures due to the stress concentrations at the blade root area of its bladed disk. Driven by the problems encountered by the steam power plant electricity generating utilities with regards to steam turbine blades fatigue failure, this study of the mistuned steam turbine blades subjected to variation in blade geometry will be of great significance to the electricity generation industry. A simplified, scaled-down mistuned steam turbine bladed disk model was developed using ABAQUS finite element analysis (FEA) software. Acquisition of the vibration characteristics and steady-state stress response of the disk models was performed through FEA. Thereafter, numerical stress distributions were acquired, and the model was subsequently exported to Fe-Safe software for fatigue life calculations based on centrifugal and harmonic sinusoidal pressure loading. The vibration characteristics and the response of the variation steam turbine geometric blade was conducted. The FEA natural frequencies compared well with published literature of the real steam turbines indicating reliability of the developed FEA model. The study found that the fatigue life is most sensitive to changes in blade length, followed by the width, and then the thickness, in this order. The analytical life cycles and Fe-Safe software shows the percentage difference of less than 4.86%. This concludes that the developed numerical methodology can be used for real-life mistuned steam turbine blades subjected to variations in blade geometry.

A highly sensitive six-conjoined-tube anti-resonance optical fiber temperature sensor based on surface plasmon resonance

ObjectOwing to advances in optical fiber sensing, sensing techniques based on surface plasmon resonance (SPR) have received much attention. In this work, an SPR temperature sensor based on the anti-resonant fiber (ARF) is designed and analyzed. By filling the core with a thermosensitive liquid, the ambient temperature in the range of 5–55 °C can be detected. MethodsThe proposed ARF was simulated utilizing the finite element analysis software COMSOL, followed by systematic and comprehensive structural parameter optimization, and the basic characteristics of the ARF-SPR temperature sensor were analyzed. Filling with a gold medium instead of the traditional coating process reduces the difficulty in manufacturing the ARF-SPR temperature sensor. ResultsThe average temperature sensitivity of the ARF-SPR sensor is 16.055 nm/°C, the minimum structural parameter sensitivity is 1.0 nm/μm, and the maximum FOM is 360.8 °C−1 at 5 °C. The ARF sensor with excellent properties has large commercial potential in biochemical analysis, temperature monitoring, as well as long-distance sensing.

Dynamic analysis of laminated composite cylindrical shells with stiffeners

The domain of engineering and structural mechanics has undergone a transformative shift, courtesy of composite materials, attributing to their remarkable strength-to-weight ratio and versatile design adaptability. Amid the diverse array of composite applications, significant attention has been directed towards composite shells fortified with stiffening elements. These configurations seamlessly amalgamate the merits of composite materials with the augmented load-bearing capabilities conferred by the incorporation of stiffeners. This research undertaking aims to dissect orthotropic multilayered shells manifesting distinct stiffening configurations. The analytical exploration is carried out through the utilization of the Finite Element Analysis (FEA) software ANSYS. The ensuing analysis embraces several stiffening patterns: no stiffener, edge beam, central stringer, three equidistant stringers, central ring, and ring with stringer. The inherent diversity in the natural frequencies is reflective of the variance in these stiffening arrangements. Keywords: Laminated Composite Shells, Finite Element Method, Stiffeners, ANSYS.

Finite element analysis of seismic behavior of PVA-ECC pier columns based on ABAQUS

In order to study the seismic performance of PVA-ECC pier column, using the finite element analysis software ABAQUS as the main research means, combined with the measured data of two existing specimens, and taking the axial compression ratio, shear span ratio and stirrup spacing as changing parameters, the extended analysis of 13 specimens was carried out, and the influence of various influencing parameters on the seismic performance of pva-ecc pier column was discussed. The results show that the established ABAQUS finite element model has a high degree of coincidence in failure morphology, hysteretic curve, skeleton curve and stiffness degradation curve; The shear span ratio and axial compression ratio have a great influence on the type performance of PVA-ECC pier column. The influence of stirrup diameter on shear capacity is less than 5%.

Effect of aggregate characteristics on properties of cemented sand and gravel

Abstract To improve the stability of cemented sand and gravel (CSG) dam construction materials, artificial aggregates can be selected to replace missing natural aggregates, and aggregate grading optimization can be carried out to meet the needs of engineering applications. This article uses finite-element analysis software to explore the influence of aggregate characteristics on the performance and destruction characteristics of CSG materials through numerical simulation. The results show that (1) with the increase of circular natural sand gravel aggregates, the peak stress and elastic modulus of the sample increase, while the strength also increases. (2) Compared to circular aggregates, polygonal aggregates have more edges and corners, which exacerbate the deformation disharmony between mortar and aggregates; the phenomenon of stress concentration is more obvious, so under the same loading step, the degree of damage of polygonal aggregates is greater than that of circular aggregates. (3) After the freeze–thaw cycle test, the deterioration of parameters in the CSG resulted in more severe damage and strength loss of the crushed stone aggregate than the circular aggregate sample. This conclusion can provide a reference for the design of CSG mix ratio in engineering sites.

A Universal Parametric Modeling Framework for Electric Machine Design

At present, the majority of electric machine design software employs its own unique machine data structure. However, when users need to transfer their designs between software, they are often faced with significant obstacles or cannot obtain a parametric model suitable for optimization. In order to solve this issue, a universal parametric modeling framework is proposed for electric machine design. The geometric structure is strictly constrained to ensure that the model will not interfere with each part because of the randomness of input parameters. A data structure consisting of points, lines, and surfaces is constructed, and a conversion interface for parametric modeling with different software is established. Consequently, this universal framework can automatically generate parametric models appropriate for different finite element analysis (FEA) software according to the input parameters. The framework is especially convenient for users who need to design or optimize an electric machine, particularly when FEA software is required for verification. Numerical verification is performed using different software based on interior permanent magnet (IPM) synchronous machines to demonstrate the effectiveness of the framework.

Fatigue Crack Extension and Life Calculation Based on Finite Element Analysis

With compact tension specimen static stress analysis and fatigue life of crack as the research object, through the three-dimensional modeling software to establish compact tension specimen, using the finite element analysis software to sample statics analysis, get the maximum deformation and maximum stress, and the compact tensile samples prefabricated crack, using the fatigue crack propagation analysis software, The cycle times and a-N curves were obtained. This method can be used to calculate the fatigue crack propagation life and visualize the crack propagation process, which is convenient to analyze and master the fatigue mechanism.

An open-source software framework for the integrated simulation of structures in fire

The traditional methods to understand the development of elevated temperature in a structure, and also the associated structural response, are not representative of realistic fire scenarios. To provide a more accurate and realistic reflection of the fire development, the current paper develops a generic middleware which interfaces between the computational fluid dynamics (CFD) software Fire Dynamics Simulator (FDS) and the finite element (FE) analysis software OpenSees. This framework enables a fully integrated simulation of a realistic fire scenario including the heat transfer through the structure and the resulting thermo-mechanical response. The proposed framework is open-source and freely available and therefore can be used and further developed by researchers and practicing engineers and customised to their requirements. This paper shows validation against two sets of experimental results and one real fire incident. A number of different types of thermal boundary conditions such as gas temperatures and heat fluxes, are obtained from the CFD analysis and are then used in the subsequent heat transfer and thermo-mechanical analysis. The primary advantage of this computational tool is that it provides consultants and designers with the means to undertake large-scale projects requiring performance-based fire engineering solutions.

Analysis of the stress field in the reactor vessel of the China Initiative Accelerator Driven System during postulated ULOF and UTOP transients

The China Initiative Accelerator Driven System (CiADS) was proposed by China Academy of Science since 2015. The subcritical reactor in CiADS is a liquid Lead Bismuth Eutectic (LBE) cooled fast reactor. When the reactor core is in operation, the LBE coolant will directly contact and corrode the inner surface of reactor vessel. Due to the high temperature, the corrosion will be more severe. If the stress on the reactor vessel exceeds the limit, the plastic deformation will occur, leading to the generation and expansion of defects and cracks, and the safety of the reactor will be affected. Therefore, evaluating the stress field of the reactor vessel under different operating conditions is a very important research project. In this paper, the finite element analysis software ADINA was applied to analyze the reactor vessel in CiADS, and the ASME Code was used as stress assessment standards. We can preliminarily prove that the stress assessments of the vessel during the postulated Unprotected Loss of Flow (ULOF) accidents satisfy the requirements of ASME Code. The limit reactivity insertion to protect the vessel from plastic deformation is 0.58$ in the postulated Unprotected Transient over Power (UTOP) accidents based on our current results. Therefore, we can preliminarily conclude that the current material selection and structural design of the reactor vessel in CiADS could survive most of the postulated transient accidents considering the stress effect.

Damage analysis and energy absorption capacity of hollow square steel tubes subjected to conical hammer impact

ABSTRACT Steel tubes find widespread applications in various structural elements, including load-bearing columns, stair guardrails, and security bollards, due to their high strength and durability. However, these structures are susceptible to damage under impact loading conditions. While prior studies have focused on drop hammer shapes like rectangles, wedges, cylinders, and hemispheres, research on the impact of a conical-shaped hammer on square and rectangular steel tubes remains limited. Therefore, this study aims to analyse the damage resulting from the impact of a conical-shaped hammer on square steel tubes using nonlinear Finite Element Analysis (FEA) software ABAQUS/Explicit. The investigation explores the effects of various parameters, including tube geometry, impact location, impactor mass, and impact height, on tube deformation and fracture behaviour of tube. Through comprehensive analysis, it was observed that the impacted site exhibited punching failure accompanied by inward bending of the tube, while outward buckling occurred at the support. The energy absorption process was examined, and the effect of the aforementioned parameters on the energy absorption capacity (EAC) was assessed. The findings indicate that the thickness of the steel tube has the most significant impact on the impact force and EAC. Additionally, the deflection of the tube was primarily influenced by the length of the hollow section.

Progressive Failure Analysis of Composite Overwrapped Pressure Vessel

Stress and progressive failure analysis (First Ply Failure to Last Ply Failure) of a composite overwrapped pressure vessel (COPV) with an aluminum liner using the finite element method (FEM) in general and commercial finite element analysis (FEA) software ANSYS in particular is presented in this paper. Ply failure prediction is based on failure criteria implemented in ANSYS software. The first-ply failure (FPF) does not necessarily imply the total failure of a laminate. After FPF, the laminate stiffness is reduced consistent with identified ply failure mode. The strength of the composite laminate is evaluated again to see if it could carry additional load. This ply-by-ply analysis progresses, until the ultimate strength is reached. In the present study the methodology is validated using benchmarks and applied to a filament wound fibre reinforced plastic composite pressure vessel with an aluminum liner. Significant results are presented and critically assessed. Directions for further work in this field are identified.

Design of energy harvesting magneto-rheological fluid damper for vehicle

Modern vehicles must include dampers in the suspension system in order to absorb vibration energy while driving. Passive dampers have dominated the market for many years. To increase the passenger comfort levels, suspension systems with controlled dampers that can adjust to uneven road profiles are needed. Semi-active suspensions have emerged as one of the most popular modern damping solution types due to their ability to manage damping force. The semi-active suspension system of the car uses magneto-rheological (MR) dampers for vibration control. The MR damper consumes low energy, has quick response, and better controllability of the damping force. A part of the energy lost in vehicle dampers can be recovered due to developments in energy-harvesting devices. This regenerated energy can be used in vehicles to power a number of extra systems, such as lighting, heating and air conditioning, and other things. This research attempts to develop an MR fluid damper with energy-harvesting rack and pinion system. The purpose of this study is to design a suspension system that combines an MR fluid damper and an energy-harvesting rack and pinion system. The design calculation involves setting the design parameters for the system that harvests energy and the MR fluid damper. Also, static structural analysis is carried out for both systems using finite element analysis software.

Dynamic Simulation Analysis of Truck Crane Based on ADAMS

Background: With a reduction in the weight of telescopic boom crane and an increase in its lifting capacity, the contradiction between its speed, stability and safety becomes more prominent. The telescopic arm also has flexible deformation during operation, which will cause vibration of the whole vehicle system. Therefore, in order to ensure safety, accuracy, and efficiency in the working process, it is necessary to accurately predict the dynamic characteristics of the telescopic boom load in the working process. Objective: The purpose of this study is to establish a rigid-flexible coupling dynamic model of the crane, which can accurately reflect the dynamic characteristics of the telescopic boom during its operation in the simulation test. Methods: In theory, this study analyzes the characteristics of a truck crane and simplifies it as a cantilever beam. Based on the Euler-Bernoulli beam theory, the vibration differential equation of the mobile masscantilever beam system is established. In the aspect of simulation, the three-dimensional modeling software Solidworks is used to establish the solid model of the truck telescopic boom, the finite element analysis software is used to establish the finite element model of the telescopic boom, and the modal neutral file is generated and imported into ADAMS to establish the dynamic model of the truck crane multi-level flexible telescopic boom. The dynamic simulation of the virtual prototype model of the truck telescopic boom crane is carried out in ADAMS software to obtain the dynamic characteristics of the key components of crane under specific working conditions. Results: The vibration differential equation derived in theory can be used to solve the dynamic response of the crane jib under specific conditions by MATLAB programming. In the aspect of simulation, the error fluctuation and its causes in the key components of the crane in the working state are analyzed, and the rationality of the virtual prototype model is verified. Finally, through the trajectory planning of the crane under typical working conditions, the purpose of stable control of the telescopic boom system of the truck crane is realized. Conclusion: The derived equation is universal for solving the vibration of crane jib in general cases. The rigid-flexible coupling model also provides a reference for the dynamic modeling, analysis, design, and manufacture of a multi-stage flexible telescopic boom. The findings of this study can provide a reference for related patent research and development.

Simulation and Analysis of Welding Spot Failure of PCB Based on ABAQUS

In the manufacturing process, the welding spot of PCB may lose efficacy because of the strain and stress impact. The reason for the occurrence of high-stress zones is the effect of the load brought by the manufacturing and assembly process. It is a giant challenge for the industry community to solve the problem of welding spots losing efficacy.In this paper, the manufacturing techniques and assembly process will be analyzed first. With the analysis result, the main impact of load would be checked. Then, with the confirmed allowable stress by calculation, the value of input stress, which may cause the welding spot to lose efficacy, would be obtained. Finally, the result of this study would be confirmed by the simulation result generated by the finite element analysis software.

Comparative analysis between Graphene and Carbon Nanotube reinforced epoxy composite

Composite structures are very high in demand because of their high strength-to-weight ratio and directional strength. The arrangement of fibers in the matrix is the major design criterion for the composites. Past studies prove that the fiber reinforcement of carbon nano allotropes such as Carbon Nanotubes (CNTs) and Graphene fibers develop reliable and durable structures for different applications. In this work, three different composite laminate sheets are designed and modeled using finite element analysis (FEA) software. Carbon nano allotropes, CNTs, Graphene, and CNT-Graphene fibers are used as reinforcements in the resin epoxy matrix. The modeled laminate sheets are analyzed for deformation and stress distribution using Hashin’s Failure criteria. The FEA results indicate that the CNTs fiber-reinforced laminate shows minimum deformation (0.000064 mm) and experiences minimum stress (3.81 MPa) compared to Graphene and CNT-Graphene reinforced laminates. The results of FEA can be used as a research basis for further study of composites in the future.

Drive simulation analysis of piezoelectric valveless micropump based on ZnO nanorod array

In this paper, ZnO nanorods are combined with the driving mechanism of a piezoelectric micropump to design a valveless piezoelectric micropump. The ZnO nanorods were prepared by the magnetron sputtering method to grow the ZnO seed crystal layer on the silicon surface and then by hydrothermal method. The growth of ZnO nanorods under different solution concentrations, solution temperatures, and growth times was investigated, and analytical methods for analyzing the surface morphology and elemental content of ZnO nanorods. Then, the simulation of the valveless micropump using ZnO nanorods prepared under optimal conditions as piezoelectric oscillators were carried out using COMSOL finite element analysis software, and the maximum output flow rate of about 14.40 μL/s was achieved at 100 V50 Hz.