Papers by Keyword: Finite Element Analysis (FEA)

Abstract: The connection between a circular hollow section (CHS) column and its baseplate plays a critical role in transferring loads from the superstructure to the foundation. However, this type of connection is often prone to stress concentration due to geometric incompatibilities between the circular column and the flat baseplate. To address this issue, stiffeners are commonly introduced to redistribute stresses and enhance the overall connection performance. Despite their widespread application, the effect of stiffener geometry on the protection of the main structural element, namely the column, has not been comprehensively studied. This study employs finite element analysis (FEA) to evaluate three stiffener configurations with F1 (triangular), F2 (rectangular), and F3 (chamfered) inn CHS-to-baseplate connections. The models were subjected to combined axial, shear, and bending loads, and the stress responses were examined in the column, baseplate, and stiffeners. The results indicate that F1 produced the lowest stress in the column (82.0 MPa), demonstrating superior efficiency in redistributing forces to other connection components. In contrast, F2 and F3 exhibited higher column stresses (123.1 MPa and 130.2 MPa, respectively), suggesting a higher risk of localized yielding. The baseplate stresses across all configurations were relatively similar (134–138 MPa), while the stiffeners showed varied levels of engagement depending on their geometry. Overall, the findings highlight the importance of stiffener design in safeguarding the column as the main structural member. The triangular stiffener (F1) proved to be the most effective in reducing stress concentration on the column, thereby enhancing the reliability and safety of CHS column-to-baseplate connections. Recommendations for future work include experimental validation, consideration of cyclic or seismic loading, and parametric optimization of stiffener geometry.

Abstract: Manufacturing defects in drill bits, especially those with helical oil holes, pose significant challenges in quality control because traditional inspection methods, like optical microscopy and fluid-based testing, often fail to detect internal defects as they are typically focused on surface characteristics. To improve defect detection in drill bit manufacturing, a vibration-based non-destructive testing (NDT) method is proposed. This approach combines finite element analysis (FEA) for simulations with experimental vibration analysis to identify frequency changes that indicate the presence of defects. The methodology now systematically includes the fundamental Bending-1 mode and employs statistical analysis (t-tests) to validate the statistical significance of detected frequency shifts and numerically express uncertainty. The results unequivocally confirm that vibration analysis can effectively distinguish defective drill bits by identifying characteristic frequency changes.

Abstract: This research presents a numerical study on the Equal Channel Angular Pressing (ECAP) process using AA6061 aluminum alloy, employing Finite Element Analysis (FEA) with ABAQUS/Explicit software. The primary objective is to simulate the deformation behavior of AA6061 under different die angles (60°, 90°, and 120°) and evaluate the simulation results by comparing them to experimental findings. The study focuses on stress distribution, plastic strain, and deformation patterns during the ECAP process to identify the optimal processing conditions. The results provide insights into the effects of die angle on the material's deformation behavior and mechanical properties, offering a foundation for optimizing the ECAP process for AA6061.

Abstract: Nanoindentation, an advanced technique employed for characterizing materials, facilitates the precise determination of their hardness and Young's modulus by applying a specific, controlled force through an indenter, enabling highly localized deformation and measurement at nanometer scales. The nanoindentation gives us the view of the isotropic and anisotropic features of the materials by analyzing the zone beneath the indenter. The application of Bulk Metallic Glass (BMG) alloy, renowned for its unique combination of high strength, exceptional elasticity, and superior corrosion resistance, spans diverse industries including aerospace, biomedical, and consumer electronics. The study focuses on conducting nanoindentation analysis on the BMG alloy, aiming to characterize its deformation behavior. This involved utilizing Scanning Electron Microscopy (SEM) to discern deformation characteristics, followed by validation of the findings through simulations, ensuring robustness and reliability of the results. The modulus, determined to be 227GPa, provided insight into the material's structural rigidity, and the hardness 14.8GPa offered an indication of its resistance to localized plastic deformation. The results have been compared with the simulation results where the modulus was 242GPa and the hardness was 16.1GPa.

Abstract: ABAQUS is a powerful software for simulating nonlinear material models with complex thermo-mechanical behavior. Its robust capabilities make it particularly suitable for simulating the Rotary Friction Welding (RFW) process. In this study, ABAQUS was utilized to simulate the RFW process of AA6061 aluminum alloy, focusing on key aspects such as weld morphology, temperature distribution, and axial shortening. The simulation results were analyzed and validated against theoretical foundations of the RFW process and previous research, demonstrating the model's high reliability. These findings highlight the potential for further development of the simulation model for various applications, aimed at enhancing the efficiency and effectiveness of RFW in industrial applications.

Abstract: This study examines electric vehicle (EV) crashworthiness with a focus on side impact scenarios affecting high-voltage (around 400V) battery packs. Using a 2001 Ford Taurus model, the research compares the performance of side door beams constructed from HSLA steel, boron steel, and Dual-Phase (DP-590) steel in crash simulations. The results indicate that boron steel significantly enhances impact resistance, minimizing battery pack damage and improving occupant safety over HSLA and DP-590 steel. The findings recommend boron steel for critical areas in EV design, with DP-590 steel emerging as an alternative option that still maintains safety standards. Future research is suggested to confirm these results through empirical testing and to investigate advanced materials for further safety improvements in EVs.

Abstract: The effectiveness of power generation of the piezoelectric energy harvester (PEH) depends on the coupling between its resonant frequency and the oscillation frequency of the vibration source. The resonant frequency of a PEH is determined by its structural design, and therefore, to improve piezoelectric energy harvester performance, the piezoelectric energy harvester must be optimally designed to achieve the resonant frequency that matches the excitation frequency of the vibration source. This paper presents the design and detailed calculation of the piezoelectric energy harvester in the form of a bimorph piezoelectric circular diaphragm (PCD) structure by finite element analysis (FEA) using the software package ANSYS. Based on analyses and calculations, the optimal structure of the piezoelectric circular diaphragm energy harvester is proposed to meet the specified resonant frequency response matching the vibration source frequency. Detailed calculations of the PEH were performed with an excitation frequency of 100 Hz. With an optimal load resistor of 10.1 kΩ, an output power of 0.287 W was generated at 100 Hz (equal to the resonant frequency of the PEH) under an amplitude of harmonic excitation of 0.1mm. In addition, the research results can be used to fabricate piezoelectric circular diaphragm energy harvester operating at a resonant frequency suitable for the available vibrations.

Abstract: This study examines the Markforged simulation software's efficacy in predicting properties of Markforged 3D-printed parts. Material extrusion (MEX) is widely used across industries for its ability to create intricate shapes with diverse internal patterns. To evaluate mechanical properties, especially due to varying infill patterns, the Markforged simulation tool is employed. Tensile test specimens based on ASTM D-638 were 3D printed using a Markforged Mark Two printer and "Onyx" material, varying layer thickness, infill pattern, and density. Deformation is simulated under a 500 N tensile load and compares to physical tests on a tensile machine, considering different pulling speeds. Results show minimal variation between simulations of solid infill patterns and experiments, regardless of speed. However, porous infill patterns exhibited notable differences. Tensile testing also revealed the impact of pulling speed on deflection for "Onyx" specimens under a 500 N load.

Abstract: The thermomechanical behavior of glass fiberreinforced polymer (GFRP) composite was studied. The thermal characteristics and the mechanical properties are determined over a temperature range from ambient to 60°C. The calcium carbonate filler of the amount 15% of the weight of the resin have been used in order to improve the mechanical proprieties and attempt to observe the possibility of replacement a part of expensive resin by cheap filler. The loading speed refers to the crosshead velocity, which has direct Proportionality with strain rate. After the specimens are exposed to temperatures ranging from 20 , 40 to 60 , the results show a greater elongation indicate a greater ductility that explain we improved the tenacity of specimens, Especially for temperature 60, this propriety is more suitable for vehicle industry. Results in terms of simulation using a code program (Abaqus) are presented, The Johnson–Cook (JC) model was chosen as the constitutive model and then the finite element solutions were compared to the experimental results. A good agreement of the numerical curves with the target loading curves was found.

Abstract: The paper is devoted to the assessment of the possibility to use a new design of a stretch die made of plastics used for fused deposition modeling (FDM) 3 D printing. Studies were conducted to assess the stress-strain state of a stretch die, from the normal pressure of a deforming sheet blank in a NASTRAN solver, using the finite element method. The convergence assessment of the simulation results was carried out for different quantities and corresponding sizes of finite elements. The optimal thicknesses of the hollow structure of the stretch die were determined by step-by-step calculations of its stress-strain state for acrylonitrile butadiene styrene (ABS) and polyethylene terephthalate glycol (PETG). On the basis of the conducted studies, a general algorithm was developed for the structural design of stretch dies made of plastics used for fused deposition modeling (FDM) printing.