Study on Temperature Control of Gravity Anchorage without Cooling Water

This paper uses Midas Fea simulation software to analyze the hydration heat of a suspension bridge anchorage mass concrete construction without cooling water. According to specific boundary conditions and convection coefficients, the concrete heating process and cooling process are simulated. Analyze the influence of surface air convection coefficient on the surface tensile stress of the cast layer, and the influence of the pouring interval on the interlayer stress of the anchor block, and the temperature difference between the inside and outside of the concrete when the anchor block is layered. It is found that reducing the surface convection coefficient of the pouring layer can effectively improve the stress condition, and the pouring interval has little effect on the stress.

Preparation and Characterization of an Injectable and Photo-Responsive Chitosan Methacrylate/Graphene Oxide Hydrogel: Potential Applications in Bone Tissue Adhesion and Repair

As life expectancy continues to increase, the inevitable weakening and rupture of bone tissue have grown as concerns in the medical community, thus leading to the need for adhesive materials suitable for bone repair applications. However, current commercially available adhesives face certain drawbacks that prevent proper tissue repair, such as low biocompatibility, poor adhesion to wet surfaces, and the need for high polymerization temperatures. This work aims to develop an injectable and photo-responsive chitosan methacrylate/graphene oxide (ChiMA/GO) adhesive nanocomposite hydrogel of high biocompatibility that is easy to apply by simple extrusion and that offers the possibility for in situ polymer and physiological temperatures. The nanocomposite was thoroughly characterized spectroscopically, microscopically, rheologically, thermally, and through mechanical, textural, and biological assays to fully evaluate its correct synthesis and functionalization and its performance under physiological conditions that mimic those observed in vivo. In addition, a finite element analysis (FEA) simulation was used to evaluate its performance in femur fractures. Results suggest the material’s potential as a bioadhesive, as it can polymerize at room temperature, shows superior stability in physiological media, and is capable of withstanding loads from body weight and movement. Moreover, the material showed remarkable biocompatibility as evidenced by low hemolytic and intermediate platelet aggregation tendencies, and high cytocompatibility when in contact with osteoblasts. The comprehensive studies presented here strongly suggest that the developed hydrogels are promising alternatives to conventional bone adhesives that might be further tested in vivo in the near future.

Novel Reactive Flex Configuration in Kiwi Wing Foil Surfboard

The creation of an ideal surfboard is art. The design and construction depend on the individual surfer’s skill level and type of the required performance. In this research, four fuselage concepts were carefully explored to meet the following unique needs: lightweight, strong, and a fast-manufacturing process. The fuselages were manufactured by compression moulding using skin and core materials. The skin material was selected to be unidirectional (UD) carbon fibre, discontinuous carbon fibre (SMC) and Filava quadriaxial fibre impregnated with epoxy, while the core material was selected to be lightweight PVC foam. To assess the mechanical performance, three-point bending has been performed according to BS-ISO 14125 and validated using Finite Element Analysis (FEA) using Ansys software. As expected, the flexural test revealed that the UD carbon fibre fuselage was the strongest and SMC was the weakest, while large deflection was seen in Filava fibre fuselages before failure, showing great reactive flex that promotes projection during surfing. The experimental results show good agreement with FEA simulation, and the locations of the physical failure in the fuselage matches the location of maximum flexural stress obtained from FEA simulation. Although all fuselages were found to carry a surfer weight of 150 kg, including a factor of safety 3, except the SMC fuselage, due to shrinkage. The Filava fibre fuselages were seen to have a large deflection before failure, showing great flexibility to handle high ocean waves. This promotes the potential use of reactive flex in high performance sports equipment, such as surfing boards. A large shrinkage must be taken under consideration during compression moulding that depends on fibre orientation, resin nature, and part geometry.

The Analytical Comparative Analysis of Electromagnetic Characteristics of Four Typical Radial Flux Permanent Magnet Eddy Current Couplers

The analytical model of a permanent magnet eddy current coupler (PMECC) is mainly used for evaluation of its characteristics and the initial optimization of design. Based on the equivalent magnetic circuit method, this paper carries out analytical modeling for four typical PMECCs composed of surface-mounted and interior permanent magnet, slotted and non-slotted conductor rotors, which provides a theoretical basis for the subsequent research in this paper. The basic electromagnetic characteristics of the PMECCs are investigated by the established analytical model. Simultaneously, the analytical results about permeance, flux density, torque and power are verified by FEA simulation. The analysis results show that the slotted CR will obtain a much higher power density, and the iron loss mainly exists in the CRs. In addition, the analytical and FEA results agree well, which proves the reliability of the proposed, nearly unified analytical model.

STATISTICAL INVESTIGATION OF I-SHAPED STIFFENED RECTANGULAR PLATE BY TAGUCHI RESPONSE EVALUATION

In this research, the buckling of stiffened rectangular plate with square opening is studied using techniques of FEA. The stiffener used for analysis is I shaped placed on edges and in vertical configuration. Critical buckling loads are determined from load multiplier values obtained from FEA simulation. The features of stiffener are further optimized with Taguchi response technique to acquire essential responses of variables with respect to yield variables. The sensitivities of various optimization parameters are also determined. The results indicated that substantial enhancement in buckling resistance can be achieved through optimized dimensions of stiffeners. For safety-factor least both lower width and upper width shows positive sensitivities with lower width sensitivity rate is 54.041 (positive) and upper width rate is additionally 54.041 (positive). Hence, both upper width measurements and lower width has same impact on factor noticed for SPSW.

Finite Element Analysis-Aided Performance Improvement of Circular Coil Assemblies Applied in Electric Vehicle Inductive Chargers

Energy efficiency and leakage magnetic field (LMF) are two important issues in inductive chargers. In this work, the maximum achievable coil efficiency and the corresponding LMF strength are formulated as functions of system parameters, and figure of merits (FOM) are proposed for assessing the efficiency and LMF performance of the coil assemblies. The target application is electric vehicle inductive chargers where the LMF is suppressed via passive shielding. The impact of the coil assembly’s geometric parameters on both FOMs is examined through a combination of finite element analysis (FEA) simulation and magnetic circuit analysis, and measures to improve the FOMs are studied Optimization of an exemplary coil assembly within given dimensional limits is conducted and the performance improvement is verified by FEA simulation results. <br>

Finite Element Analysis-Aided Performance Improvement of Circular Coil Assemblies Applied in Electric Vehicle Inductive Chargers

Energy efficiency and leakage magnetic field (LMF) are two important issues in inductive chargers. In this work, the maximum achievable coil efficiency and the corresponding LMF strength are formulated as functions of system parameters, and figure of merits (FOM) are proposed for assessing the efficiency and LMF performance of the coil assemblies. The target application is electric vehicle inductive chargers where the LMF is suppressed via passive shielding. The impact of the coil assembly’s geometric parameters on both FOMs is examined through a combination of finite element analysis (FEA) simulation and magnetic circuit analysis, and measures to improve the FOMs are studied Optimization of an exemplary coil assembly within given dimensional limits is conducted and the performance improvement is verified by FEA simulation results. <br>

Design and simulation of mechanical press for testing of coining tools with nanostructured coatings

The present study proposes the design, simulation, and finite element analysis (FEA) of a mechanical press to test coining tools that contain nanostructured coatings. The designed mechanical testing press has a nominal force capacity of 800 kN with a ram stroke of 100 mm. CAD modeling of components, assemblies, and press structure is developed. The validation of the safety factor of the stress of the press is implemented by FEA analysis. Axisymmetric 2D FEA simulation is applied to determine the nanostructured coating behavior when subjected to high loads, the results are promising for future simulation studies on coatings. A displacement mechanism was designed for the test sheet, offering versatility and a variety of options for testing the coining tools as often as necessary under different load conditions. The final results of the machine operation simulation are satisfactory.

Sound absorption of a thick micro-perforated panel with tapered sections

This article aims to investigate the sound absorbing properties of a thick microperforated panel (MPP) with tapered sections with finite element analysis (FEA) models. The FEA model was validated by using the measured sound absorption coefficients of a classic MPP sample and a proposed MPP sample. The FEA simulation and the experiments indicate that the tapered section can enhance the sound absorption coefficient. Moreover, the FEA model shows that the structural parameters of the tapered section can be optimized. The resonance frequency of the sound absorption coefficient moves to the high-frequency range, and the maximum sound absorption coefficient increases in three conditions, the tapered section moving toward the backing cavity, and the increase of the thickness and the bottom radius of the tapered section. Although the optimized configurations of the tapered section may vary with the structure parameters of the MPP, the tapered section can improve the sound absorbing properties of the classic MPP and could be promising in the noise and vibration engineering projects.