Papers by Keyword: Stiffness

Abstract: This paper summarizes the comparison of seismic performance between single and double unit tunnel form building (TFB) under in-plane lateral cyclic loading. Experimental work was carried out to determine the lateral strength capacity, stiffness, ductility, and equivalent viscous damping (EVD) for both specimens. The comparisons of these parameters for both specimens were made to determine its percentage difference. The maximum lateral strength capacity obtained from single unit TFB with 8.68% higher than double unit TFB. As for stiffness behaviour, single unit was found to be much more stiffened compared to double unit. The EVD value showed that single unit absorbed much more energy compared to double unit of TFB. However, double unit TFB indicated a significant percentage of increment compared to the single unit TFB. Therefore, double unit TFB is safer to be built compared to single unit especially for seismic regions.

Abstract: The mooring system initial design is quasi-static method based on catenary method. The mooring line stiffness derivation also base on catenary method. In the paper, using jumping wire of high voltage cable calculation method, design the mooring system. Building initial design model, considering the mooring line stiffness and drift angle of mooring line and structure.

Abstract: Sandwich panel structures are increasingly used in applications where the most important demands are the weight saving and long service life. Utilizing sandwich panels, extremely light-weight, stiff and robust structures can be manufactured. In this study, sandwich panels were produced by specially designed cost-effective forming tools. Various kind of test materials were used for corrugated cores and skin plates: conventional low-carbon steel grade EN 10130 and ferritic stainless steel grade 1.4509 with plate thicknesses of 0.6 and 0.75 mm. A common S355 structural steel was used as a reference for bending strength comparison.For measuring the stiffness, MTS tensile and fatigue testing machine was selected to determine the bending resistance of the sandwich panels. The bending force, needed for yielding and fracture, related to the bending length and intensity was compared with the results from bending of the reference plates. Results showed that the bending force of the panels is significantly higher than that of a plate having similar intensity. The best results were obtained with the stainless steel (SS) panel that had 27% higher bending force at the yield point than 5 mm thick S355 plate having 3 times larger intensity. The carbon steel panel was approximately 40% weaker than the SS-panel and both panel types lost strength when loading direction was changed from transverse to 45 degree and further to 90 degree load (longitudinal).

Abstract: Bottom frame-shear wall structure is a kind of special structure, due to the inharmonious relationship between the frame and masonry walls in bearing lateral capacity and deformation ability, the difference of vertical stiffness in the bottom frame-shear wall structure is bigger, so the structural seismic performance is poor. A six layer bottom frame-shear wall structure seismic strengthening project is established in order to contrastive analyze two kinds of reinforcement scheme, which are additional RC shear wall and additional buckling constraints. Calculation and analysis results show that through setting buckling constraint support in the bottom layer of reinforced concrete frame and selecting rational mechanical parameters, can increase lateral stiffness, reduce the lateral deformation and realize the effect of multichannel fortification. At the same time, the advantage of easy to implement is belong to bottom frame-shear wall structure.

Abstract: Taking structure strengthen of a large hotel as the engineering background, based on superposition principle, put forward the design method of concrete two-way slab strengthened with partially bonded steel plate. According to the finite element analysis, the solid finite element model is established, and then the stress, strain and deflection of two-way slab strengthened with bonded steel plate is obtained, at the meantime compared with the load test datum in situ. The analysis results show that the finite element software is a reliable tool applied to analyze the design of two-way slab strengthened with bonded steel plate. When the increasing load is larger, partially bonding steel plate strengthening has more advantage and economize than bonding carbon fiber strengthening on two-way slab, meanwhile that slab strengthened with partially bonded steel plate has better mechanical properties, strength and stiffness.

Abstract: Established a finite element model of the school bus based on the Hyper Mesh, take a finite element simulation about the various parts of the school bus parameters such as stress, displacement and deformation under 5 conditions. Through the analysis of the school bus to identify conditions displacement of stress more concentrated area as well as in operation, by optimizing improve the local structure of these regions,improve the stress concentration and safety.

Abstract: The finite element method to obtain the stiffness of MEMS (Micro-Electro-Mechanical Systems) accelerometer is difficult to give an exact expression, so a new method to analyze the stiffness of MEMS accelerometer was purposed. Both Mechanics and electricity analysis were used to calculate the stiffness of vacuum microelectronic accelerometer developed in our laboratory, and the control and detection circuits were design according to the result. Finally, the sensitivity, linearity and other performance were measured through the static gravitational field experiments; the least squares curve fitting correlation coefficient 0.9999 and linear 0.9%. The result shows that this method to analyze the stiffness of the stiffness of vacuum microelectronics accelerometer is correct and feasible, and this method can also be applied to other MEMS accelerometer with symmetrical structure and electrostatic force balance mode.

Abstract: In this paper, two different beam elements (i.e. according to the Bernoulli beam and Timoshenko beam theory) for the modeling of the behavior of carbon nanotubes are applied. Finite element models are developed for this study with variation of chirality for both zig-zag and armchair configurations of CNTs. The deformations from the finite element simulations are subsequently used to predict the elastic stiffness and the critical buckling load in terms of material and geometric parameters. Furthermore, the dependence of mechanical properties on the kind of beam element and the mesh density is also compared. Based on the obtained results, Youngs modulus and critical buckling load of structures using Timoshenko beams are clearly lower than the Bernoulli beam approach for all chiralities.

Abstract: The present study aimed at obtaining torsional stiffness, bending stiffness and stiffness center position of full composite wing using thin wall structure mechanics theory. The influence of stringer layout on wing integer structure stiffness was furthermore investigated. It was found that wing section stiffness was influenced by stringer layout and dimension. The best spacing of stringer was within the range from 130 mm to 150 mm, at the same time, stringer stiffness had more change by the differences of its numbers. The study of this paper provided important support for structural design and aeroelastic analysis on composite wing.

Abstract: Excessive bleeding becomes a primary cause for war wound death, accident death and operative death. Therefore, decreasing the bleeding time and operation time were play an important role in the preoperative period. In this study, the Tencel^® fiber and high absorbent fiber were used to produce high absorption composite nonwoven fabrics. As the result of experiment, the higher high absorption fiber that will create the high stiffness, in addition, the nonwoven has upper stiffness at cross direction. In wicking behavior, the composite nonwoven has about absorption water reach 14 g when the high absorption fiber was 50 wt%. The assessment of application for this study anticipated the resulted high absorption composite nonwoven fabrics to be used as hemostasis material to decrease the ratio of dead person on bleeding.