Papers by Keyword: Bracket

Abstract: The previous research on beam and column connections made of laminated bamboo with steel brackets has been tested under static loads. Furthermore, these connections need to be studied for their performance in terms of energy dissipation. The test specimens will be subjected to two-way lateral (cyclic) loading treatment. The testing and analysis standards used include ASTM E2126-11, AISC 360-16, Eurocode 1993-1-8, and Eurocode 1998-1. The results showed that the configuration of the number of thread rods used and the size of the thread rod cross-sectional area affected the moment values achieved. In addition, the trends formed in the curves show that the first loading cycle has a greater bending moment capacity than the second loading cycle. The results show that loading history, bracket usage, configuration, and thread rod cross-sectional area affect the dissipation energy values; the highest dissipation energy value is 527.89kJ for 10.6 configuration specimen and the smallest dissipation energy value is 159.80 kJ for 6.4 configuration specimen. Additional results show that test specimens with six thread rod configurations are classified as medium energy dissipation class (DCM), and test specimens with four thread rod configurations are classified as low energy dissipation class (DCL). Test specimens with configurations 6.4, 8.4, 8.6, 10.4, and 10.6 showed service failure.

Abstract: The performance of bracket component is low with uneven micro-structure, internal porosity and shrinkage defects produced by traditional liquid die casting process which cannot be strengthened by T6 heat treatment. In this paper, the aluminum alloy bracket with high-performance and light weight was prepared by a novel semi-solid slurry preparation technique that included chilling rod stirring and funnel-shaped cylinder device, which rapidly reducing the liquid temperature to near liquidus and realizing explosive nucleation. The effects of pouring temperature and CRS process on the microstructure and mechanical property of bracket were studied by optical microscopy (OM) equipped with polarizing mode and bench failure test. The results show that the as-cast microstructure mainly consists of near-spherical α-Al. And the semi-solid micro-structure was affected by these two critical parameters, the pouring temperature and CRS process. Without the condition of stirring, the micro-structure is typical dendritic with a certain proportion of fine spherical crystals, which was mainly generated during the filling of die casting process. And with the addition of the chilling rod, the finer and more uniform spherical semi-solid micro-structure was obtained with the lower pouring temperature. Based on the above semi-solid process and flow controlling through the mould design and vertical die casting process optimization, the high-performance bracket component without shrinkage can be prepared. Additionally, compared with the liquid die casting process, the internal quality and bench testing force of bracket prepared by CRS vertical die casting process are significantly improved.

Abstract: To evaluate and compare shear bond strength (SBS) and Adhesive Remnant Index (ARI) of orthodontic brackets polymerized by high-intensity light-emitting diode (LED) curing units at different intensities and curing times. Sixty extracted human upper premolar teeth were divided into 3 groups of 20 each. The tooth surfaces were prepared and the brackets were bonded on the teeth with light-cured adhesive and cured with 3 different light-curing units and conditions; Group 1 (Bluephase, 1,200 mW/cm², 20 seconds), Group 2 (VALO, 3,200 mW/cm², 6 seconds), Group 3 (FlashMax P3, 4,000-6,000 mW/cm², 3 seconds). Shear bond strength of the specimens were tested after bracket bonding for 5 minutes. The means of shear bond strength among groups were compared by Kruskal-Wallis and Mann-Whitney U tests. ARI were tested by the Fisher's exact test (p < 0.05). The means and standard deviations of SBS in groups 1, 2 and 3 were 21.80 ± 2.85, 21.04 ± 2.87 and 4.75 ± 2.82 MPa, respectively. Group 3 had significantly lowest mean SBS. Significant difference of ARI was found between Bluephase and VALO groups (p = .010). FlashMax P3 curing at 3 seconds generated significantly lowest mean SBS among 3 groups. The SBS generated by VALO curing at 6 seconds was not significantly different from Bluephase curing at 20 seconds. Therefore, VALO can be an option for orthodontic bracket bonding benefited in reducing clinician chairtime and patient discomfort.

Abstract: In order to eliminate the resonant of engine bracket and front frame caused by the vibration during engine work period, the damping bracket was introduced between front frame and explosion-proof diesel engine for Framework-type Roof-Supporter Transport Vehicle (FRSTV). The harmonic response analysis of front frame was conducted with ANSYS Workbench. The results can be used for the vibration prediction.

Abstract: In the paper, the three-dimension model of the naval gun including barrel, cradle, bracket .etc has been built in the environment of Pro/E, which Provides the necessary conditions for the building of the dynamics equivalent mode. Then, finite element analysis software ABAQUS had been used to create the finite element model of the naval gun. Apply the above model to simulate the process of shooting with an angular altitude of zero. The characteristics of structural dynamics response of the gun are obtained through analysis. Through the comparison from the result, the stiffness and strength of the naval gun is verified and the basis to improve the firing accuracy is provided. With the method of this thesis, much work such as verifying scheme, finding design bug, verifying firing accuracy, evaluating stiffness and strength of the gun can be done through simulation in the stage of gun design, then period of design is shorted and cost of design is also reduced.

Abstract: Since the bracket deformation caused by its deadweight is too large, and the riveting of aircraft panel is always over-tolerance, a new algorithm for analysis and compensation of bracket deformation is presented in this paper. The algorithm is formed by combining finite element (FE) simulation with analytic method, which is fit for different combinations of supporting plates of bracket system. The formula is constructed through cubic spline interpolation and envelope surface fitting according to the FE simulation data. Meanwhile, a corresponding compensation method is proposed. Finally, a numerical simulation example with the software of ABAQUS shows that the algorithm and its results are valid and feasible.

Abstract: The paper aims to design a kind of bracket of scraper part of coal mine underground horizontal extension Transfer Machine perfectly, based on Solid Works. And we would like to perform numerical simulation for the bracket, furthermore to optimize the transect parameters and achieve that to reduce the weight of the bracket. At last, through optimization design, we prefer to reduce 4.5% in Von Misses press and 15% in weight. In this way, we can offer a useful reference to design the bracket of scraper part of coal mine underground horizontal extension Transfer Machine.

Abstract: Aiming at the center shaft bracket sheet extension parts, its stamping calculation is simulated based on the sheet metal forming with nonlinear finite element software Dynaform. The contours varying with blank holder forces, friction coefficients and material performance parameters (sheet hardening exponent n and thick anisotropic coefficient r) are obtained by using the simulation software. The impact of the factors on the central shaft bracket parts stamping is analysised by using the contours, provide the theory to eliminate the fold and fracture in the stamping process.

Abstract: One of the main logistics function is handling and transporting which happens with very high frequency in the logistics system and occupies an important part of logistics cost. An automated handling system, such as shelves manipulator bracket, is quite necessary because of its cost of large manpower and time. According to the software Solidworks, the model of the shelves manipulator bracket can be established and analyzed by the plug-in of COSMOS Works. The loads and boundary condition of the bracket is calculated through the actual situation, and the stress characters has been obtained as soon as pretreatment is done. The FEA method that used by Solidworks has provided a new though about logistics devices.

Abstract: This paper introduces a die-casting mold design process. On the basis of the shape of Car oil pump support, central of castings’ side face was selected as the mold joint; due to the design requirements of pouring system, we chosen bias running system. Castings’ size was calculated by requirement of die casting machine, then accomplished designs of molding and structure’s components. Because through holes which on the side face of castings are not deep, angular pin core puller is competent, at last, the final assembly of the mold and the simulation is completed.