Papers by Keyword: Finite Element Simulation

Abstract: This study introduces a novel flowformability test aimed at replicating the complex loading conditions of industrial flowforming processes—alternating stress triaxiality, large plastic strains, and high strain rates. A novel Conical Flowformability Test (CFT) configuration was selected for experimental validation due to its ability to achieve a high theoretical thickness reduction while respecting machine constraints. Experiments conducted on AA6061 in O-temper and W+3h states demonstrated substantial thickness reductions. Comparison between the numerical simulations using the software FORGE® and the experimental results is satisfactory despite certain unquantifiable experimental defects such as fish scales and material build-up. The current study paves way to establish a robust framework for assessing material flowformability and damage evolution under realistic process conditions.

Abstract: The early failure of single-lap adhesive joints in carbon fiber reinforced polymer (CFRP) composites is typically induced by stress concentration at the edges of the overlap region. To address this issue, this study proposes a novel local pre-curing process system based on gradient thermal curing regulation. Through multi-physical field modeling of the temperature-curing coupling effect and a gradient curing control strategy, active optimization of the adhesive layer stress distribution is achieved. By optimizing the interface stress distribution, the proposed technique demonstrates the potential to enhance the overall joint performance by 3-6%. This research combines Abaqus finite element simulation and experimental verification. A CFRP single-lap joint model considering the temperature-curing coupling effect was established to analyze the influence of local pre-curing on the stress distribution of the adhesive layer. The results show that: 1. Local pre-curing can reduce the peel stress in the critical edge danger zone by about 3 - 5% while improving the shear strength in the middle region. 2. The preferential curing at the center of the adhesive layer can induce stress redistribution, relieve the stress concentration at the edges, and thus improve the overall load-bearing capacity of the joint. This study provides a low-cost and easily implementable solution for optimizing the performance of CFRP joints, showing potential applications in the field of lightweight aerospace structures. Through the synergistic effect of precise thermal management and regulation of the adhesive's rheological properties, it offers new insights for advanced composite joining technologies.

Abstract: The three-period minimal surface (TPMS) metal porous structure represents a novel design suitable for lightweight and multifunctional applications. This study designed three types of TPMS porous structures: Diamond, Gyroid, and Primitive, and investigated their deformation behavior through finite element simulation. Results indicate that the Gyroid structure demonstrates exceptional mechanical properties and energy absorption, achieving a strength limit of 186.44 MPa. The Gyroid porous structure exhibits a uniform layer-by-layer fracture pattern with a fracture zone at a 45° angle to the direction of pressure loading at 30% strain. Conversely, at 20% strain, the Diamond and Primitive porous structures exhibit initial shear band failures at the unit cell junctions.

Abstract: With the acceleration of urbanization and the expansion of densely populated areas, the safety and durability of building structures in metropolitan areas have become increasingly significant issues. This trend has raised the requirements for building materials, particularly in the production of prefabricated building components, where the use of high-strength, high-toughness concrete has become the norm. Using high-toughness concrete reinforced with organic fibers can enhance the mechanical properties of concrete while ensuring good workability, and POM fibers are among the most widely used organic fibers. This study primarily investigates the mechanical properties of prefabricated hollow wall panels made from high-toughness concrete reinforced with POM (polyoxymethylene) fibers. The mechanical behavior of POM fiber-reinforced concrete was analyzed through laboratory tests, including assessments of compressive and tensile properties. The results indicate that the inclusion of POM fibers significantly improves the maximum elastic compressive strength and ultimate compressive strength of the concrete, as well as enhancing its tensile capabilities. Using the CDP model theory in finite element analysis, this study further calculated the structural response of high-toughness concrete prefabricated hollow wall panels under wind and seismic loads, demonstrating their practical feasibility in engineering applications. This research not only provides a scientific basis for the application of POM fiber-reinforced high-toughness concrete but also offers new directions for future research and application in building materials, particularly in urban constructions requiring high safety and durability.

Abstract: PVA fiber reinforced toughness-concrete is widely used in masonry structure reinforcement due to its cost-effectiveness and excellent toughening effects. The tensile strength of the material significantly impacts the shear capacity of the masonry. This study systematically investigates the effects of fiber length and dosage on the uniaxial tensile behavior of PVA fiber reinforced toughness-concrete through finite element simulation and axial tensile tests. Additionally, the specific influence of fiber inclusion on the material’s tensile strength was analyzed through experiments and fitting calculations. The results indicate that optimizing the length and dosage of fibers can significantly enhance the tensile performance of the toughness-concrete. Consequently, this research has optimized the mix proportion of the toughness-concrete, thus balancing reinforcement effectiveness with material cost optimization. These achievements not only enhance the structural safety and durability of the reinforced masonry but also have significant practical implications for improving the shear carrying capacity of masonry structures.

Abstract: The aviation and automobile sectors have witnessed significant expansion and demand for lightweight metals. The friction stir welding (FSW) procedure is used for joining lightweight and low melting temperature materials. A Finite Element Analysis (FEA) utilising COMSOL® Multiphysics 6.0 software is utilised in this article to combine dissimilar metals AA6061-T6 and Mg AZ31-B, and their thermo-mechanical characteristics are explored. The peak temperature was observed to increase to 448K and 928K when the coefficient of friction (COF) increased from 0.01 to 0.4, while other parameters remained constant. When the tool rotational speed is increased to 500, 600, or 700 rpm, the peak temperature climbs to 658 K, 706 K, and 759 K, while all other parameters stay constant. When the welding speed is increased, the peak temperature reduces from 665K, 649K, and 638K to 45mm/min, 60mm/min, and 75mm/min, with all other parameters remained constant in this study. The peak temperature climbed to 632K, 684K, and 759K when the axial force increased to 10 kN, 15 kN, and 20 kN, respectively, which is a tolerable temperature less than the point of melting of materials. Peak temperatures increase to 628K, 630K, and 635K when the shoulder-to-pin diameter ratio increases to 2.5, 3.0 and 3.5 with all other parameters remaining constant. As a result, the peak temperature is directly related to tool rotational speed, coefficient of friction, axial force, and shoulder-to-pin diameter ratio, whereas welding speed is inversely proportional.

Abstract: Three-dimensional finite element modeling (FEM) has been carried out using QForm software on the hot forging operation of the upper ball joint, involving the process of roughing and finishing. The material used is SNCM8 commercial alloy steel. This paper aims to optimize the initial billet size to achieve a final forged product without any defects. To accomplish this task, it was necessary to determine the initial optimum billet size by calculating the mass ratio. It is more practical to reduce the length of the initial billet and keep the diameter constant. The initial billet size was obtained by FE simulation by varying the five cases of mass ratio. The minimum dimension of the initial billet, which filled the die cavity without defects, was selected for the tryout experiments. The experimental results supported the FEM results and indicated that the optimum size was ∅48x152.88 mm, which may reduce material waste by 17.65%. Additionally, the forging load during the forging process was investigated. The actual forging load was slightly higher than the experimental one. The forging load showed a maximum error about 10.13%. Finite element simulation by QForm V10.1.6. software is recommended as an efficient tool for predicting the hot deformation behavior of the material during several stages of hot forging, which can save material costs and the cost of trials, leading to enhancements in the manufacturing process.

Abstract: Forming conditions for deep drawn SUS304 square cups having no delayed cracks are determined using finite element (FE) simulations based on the threshold % of wall thickening for delay cracking obtained from deep drawing tests of SUS304 cylindrical cups. The maximum drawing ratio and the initial blank thickness are fixed at 1.87 and 0.8 mm, respectively in this study taken into the considerations of the capacity of the press machine i.e., 100 kN. The blank holding forces (BHF), punch corner radius, r_p and die corner radius, r_d are varied to obtain 75 mm x 75 mm square cups having % of local thickening less than the threshold value i.e., 47% in the cracking zones located adjacent to the top corners of the cups. A quarter 3D FE simulation model of the deep drawing process is constructed, the wall thickness distributions of the cups are calculated. The simulation results showed that the forming conditions for the crack-free cups could be obtained with BHF ≥ 47 kN, r_p ≥ 8.5 mm and 6.8 mm ≤ r_d ≤ 9.5 mm. A method for designing the forming conditions of deep drawn SUS304 square cups is proposed in this study.

Abstract: This paper used finite element analysis of metal forming to study the forging process and die design of aluminum alloy brake parts. According to the process parameters and die design, the brake parts were forged by experiment. First, the die design is based on the product size and considering parting line, draft angle, forging tolerance, shrinkage and scrap. Secondly, the finite element analysis of metal forming is used to simulate the forging process of aluminum alloy brake parts. Finally, the aluminum alloy brake levers with dimensional accuracy and surface hardness were forged.

Abstract: Bipolar plate is the key component of proton exchange membrane fuel cells. Due to the factors of rapid and mass production, the stamping process is selected to manufacture the bipolar metal plates. First, the stress-strain curve is performed by universal material testing machine.The stress-strain curve is necessary for bipolar plate stamping simultion. The maximum forging load and effective stress distribution of bipolar plate stamping are determined by finite element analysis. Finally, the effect of the traditional crank stamping on the flatness and section thickness of stainless steel bipolar plate are observed by experiments.