https://dspace.ctu.edu.vn/jspui/handle/123456789/13 Trung ương Hội KHKT Cơ Khí VN & Hiệp hội Doanh nghiệp Cơ khí VN Mon, 12 Oct 2026 15:44:09 GMT 2026-10-12T15:44:09Z http://localhost:8080/jspui/retrieve/cdf9dbc8-2d7e-46a2-a464-e2009939d889/01 (29).jpg https://dspace.ctu.edu.vn/jspui/handle/123456789/13 https://dspace.ctu.edu.vn/jspui/handle/123456789/130062 Title: Influence of artificial neural network architecture depth on surface roughness prediction in finish milling of 6061 aluminium alloy = Ảnh hưởng của độ sâu kiến trúc mạng nơ-ron nhân tạo đến dự đoán độ nhám bề mặt trong gia công phay tinh hợp kim nhôm 6061 Authors: Huynh, Thanh Thuong; Bui, Van Huu Abstract: This paper investigates the influence of Artificial Neural Network (ANN) architecture depth on surface roughness prediction during finish milling of 6061 aluminium alloy. Experimental data were obtained from a Taguchi L27 design involving cutting speed, feed rate, and depth of cut. Twenty-one samples were used for training and six for internal testing, while six additional experiments outside the original design space were employed for external validation. ANN architectures containing one to four hidden layers were developed and evaluated using R², MAE, MAPE, and RMSE. All models achieved high accuracy on internal testing data, but the two-hidden-layer ANN provided the best performance with R² = 0.9970, MAE = 0.0124 µm, and RMSE = 0.0154 µm. External validation further confirmed its superior generalisation, achieving R² = 0.8715 and RMSE = 0.0333 µm. Deeper three- and four-layer architectures exhibited overfitting and reduced robustness. The results demonstrate that moderate network depth provides an effective balance between predictive accuracy, model complexity, and generalisation for machining applications with limited experimental datasets. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.ctu.edu.vn/jspui/handle/123456789/130062 2026-01-01T00:00:00Z https://dspace.ctu.edu.vn/jspui/handle/123456789/130061 Title: Crystal orientation dependence of crack growth and crack-tip deformation in iron–3 wt.% Si single-crystal thin plates = Sự phụ thuộc của hướng tinh thể đối với sự phát triển vết nứt và biến dạng tại đầu vết nứt trong các tấm mỏng đơn tinh thể iron–3 wt.% Si Authors: Huynh, Thanh Thuong; Bui, Van Huu Abstract: This paper investigates the influence of crystallographic crack orientation on crack growth and crack-tip deformation in Fe-3 wt.% Si single-crystal thin plates. Two crack orientations, (101) [010] and (010) [101], are examined through displacement-controlled uniaxial tensile tests at room temperature. Crack propagation is continuously monitored using optical microscopy, while post-test surface morphology and slip activity are analyzed by scanning electron microscopy. Stable ductile crack growth occurs in both orientations, but significant differences are observed in crack-growth rate and crack-tip deformation. The (101) [010] orientation exhibits substantially larger crack-tip opening angles, extensive slip activity, and pronounced crack-tip blunting, whereas the (010) [101] orientation shows smaller opening angles and faster crack propagation. These differences are attributed to orientation-dependent slip activation and interactions between in-plane and out-of-plane deformation near the crack tip. The results demonstrate that crystallographic orientation strongly governs crack-growth mechanisms by controlling local plastic deformation and dislocation behavior, providing fundamental insights for texture-controlled design of Fe–Si alloys with improved crack resistance. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.ctu.edu.vn/jspui/handle/123456789/130061 2026-01-01T00:00:00Z https://dspace.ctu.edu.vn/jspui/handle/123456789/130060 Title: Numerical benchmark simulation of explosion problems according to NATO TTA 705 using Altair HyperWorks RADIOSS = Mô phỏng số các bài toán nổ đối chứng theo tài liệu NATO TTA 705 sử dụng phần mềm Altair HyperWorks RADIOSS Authors: Hoang, Van Nam; Do, Xuan Thanh; Bui, Van Phat Abstract: This paper presents a numerical benchmarking study to evaluate the reliability and applicability of Altair RADIOSS for blast dynamics and structural failure simulations according to NATO TTA 705/GEN301. Two representative problems are investigated: propagation of an air-blast wave generated by a 100 mm diameter spherical explosive charge positioned 2 m above the ground, and explosive cutting of a 30 mm thick steel plate. The air domain is modeled using a multi-material Arbitrary Lagrangian-Eulerian formulation, while structural failure is simulated using a hybrid FEM-SPH technique with the Johnson-Cook material model. Comparison with the Sadovsky empirical formulation shows that simulated peak overpressure deviations range from 26% to 32%, while preserving the expected attenuation trend with distance and shock-wave reflection behavior. For the steel-cutting benchmark, the model reproduces crack initiation, material fragmentation, and complete separation, with maximum equivalent von Mises stress reaching approximately 1457 MPa. The results demonstrate the suitability of Altair RADIOSS for blast-resistant military structural analysis and design. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.ctu.edu.vn/jspui/handle/123456789/130060 2026-01-01T00:00:00Z https://dspace.ctu.edu.vn/jspui/handle/123456789/130059 Title: Calculation and design of a Podjet-type hanging waterjet nozzle (size 330) = Nghiên cứu tính toán và thiết kế ống phụt kiểu treo Podjet size 330 Authors: Hoang, Van Nam; Pham, Tien Dung Abstract: This paper presents the calculation, design, and hydrodynamic evaluation of a Podjet-type hanging waterjet nozzle (size 330) for amphibious vehicle propulsion systems. The study combines theoretical analysis with computational fluid dynamics simulation. A three-dimensional model of the nozzle, impeller, and flow domains was developed in SolidWorks, while CFD analysis was performed using SolidWorks Flow Simulation based on the Reynolds-averaged Navier–Stokes equations and a two-equation turbulence model. The theoretical model was used for preliminary performance estimation, whereas CFD simulations evaluated thrust and power under bollard-pull and forward-speed conditions. At an impeller speed of 2088 rpm, the CFD model predicted a maximum thrust of approximately 7.869 kN and shaft power of 57.4 kW, with deviations of 4.3% and 6.5%, respectively, from MJP330 manufacturer data. Under forward-speed conditions, thrust generally decreased as vehicle velocity increased, while deviations remained generally within 10%. The results support the feasibility of domestic design and provide a basis for further geometric optimization and experimental validation. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.ctu.edu.vn/jspui/handle/123456789/130059 2026-01-01T00:00:00Z