Papers by Keyword: Structure Design

Abstract: Concrete is a fundamental component of many structures and the backbone of the construction industry. While normal-strength concrete is typically used for smaller projects, high-strength, and even ultra-high-strength concrete are increasingly employed in large-scale construction. This type of concrete provides greater structural strength and reduces costs by minimizing the size of structural members compared to normal-strength concrete. High-strength concrete offers additional benefits such as enhanced durability, reduced permeability, and improved resistance to environmental conditions. High-strength concrete can be produced using various admixtures, including fly ash, silica fume, sugarcane bagasse, and rice husk ash. This study focuses on developing high-strength concrete suitable for high-rise buildings and infrastructure projects. This research used silica fume as a partial replacement for cement in varying proportions (5% to 15% by weight) along with highlighting the optimal percentage of silica fume replacement to achieve best performance. The mix designs utilized Sargodha and Margalla crush aggregates, with water-to-cement ratios ranging from 0.30 to 0.35. Concrete samples were cast and tested to evaluate key properties, including compressive strength, tensile strength, workability and modulus of elasticity. The study shows that incorporation of silica fume in high-strength concrete significantly enhances its mechanical properties, including workability, compressive strength, and tensile strength. The results showed marginal improvements in the modulus of elasticity as the silica fume content increased. By using high-strength concrete, designers can reduce material usage due to smaller member sizes, making it particularly valuable for high-rise buildings, long-span bridges, and offshore structures. The research concludes with recommendations for future work and further applications.

Abstract: Uniform standard in the structural design for insulated tubular bus is not available both at China and abroad, and there are few reports about insulated tubular bus, which causes a waste of resources and even leads to grid failure. In this paper, epoxy/paper composites insulated tubular bus was investigated and a two-dimensional model was preferred in the simulation due to the axial symmetry of insulated tubular bus. The distribution of electric field and temperature in composite insulated materials were studied with the changes of the diameter/thickness of copper pipe and the thickness of insulation materials. According to the results simulation results, the structure of insulated tubular bus was optimized, the thickness of copper pipe conductor and insulation had been greatly reduced. Compared to the non-optimized initial structure, the amount of copper pipe conductor used for the optimized insulated tubular bus was reduced by 48%, the amount of insulation materials were reduced by 52.5%, and the current density of copper pipe conductor increased by 92.2%.

Abstract: For the purpose of weight saving, the heavy metal articulated platform, which is used in Bus Rapid Transit (BRT) vehicles to connect the front and rear compartments, is replaced with carbon fiber composite material. Composites articulated plates are designed based on the requirements of shape, size, positioning, connection and load of steel articulated platform. Optimization design is applied to high stress region in the articulated plates to provide references for the improvement and lightweight design of the articulated platform.

Abstract: The paper presents a consolidation solution to a damaged construction due to its emplacement on difficult foundation soils and inadequate foundation design. Because of the long building operation, many difficulties arise out of structures some frequently met being produced by the unequal settlement of soil, incomplete design of foundation systems or adoption of constructive solutions for foundations apart from design stipulations. To carry out the sustainable performance of structures and actual deformations of structures, foundations, and foundation soils, the current characteristics of the materials being used are necessary to be assessed as well as to evaluate and identify the proper measures to bring them up to the imperative level that ensures safe, reliable and efficient operation. The paper aims to bring in practical ways for the rehabilitation of structures influenced by the inappropriate foundation design as well as difficult sites presenting not only some real deficiencies arisen in structural elements but also methods and technologies used to enhance the performance of constructions in terms of structural capacity and serviceability. The paper shows specific causes that produce structural degradations and the results got from a case study defining two possible solutions emphasising that the consolidation works are specific to each and every building needing experience in expertise, design and execution.

Abstract: The continuous growth of labor Cost, Study on the flexible robotic polishing systems has important realistic meanings. In this paper, After fully understanding the requirements of designing polishing tool based on polishing technology, a robot end-effector polishing tool held by the arm of robot is designed, and the establishment of a dynamic model and the equations of motion dynamics, which to provide technical support and theoretical basis for further development and optimization of flexible robotic polishing systems.

Abstract: In some areas such as micro-mechanical, ultra-precision machining, nanotechnology, the high-precision positioning and very fine vertical scanning motion are needed urgently. Therefore, the Z-axis micro-displacement driving control technology has become the key technology in these areas. The piezoelectric ceramics actuator and stepper motor were integrated into hybrid linear actuator in Z-axis nanopositioning stage, and this can simplify the structure of the drive system. By calculating the gravity center of the vertical scanning system, and using single counterweight, a new one-arm bridge type structure was built. Appropriate tension and current sensors were also equipped in order to real-time monitor the drive status. It is feasible to balance the weight with this simplified system structure, and also guarantee the driving control accuracy of nanopositioning stage. Besides, in the structural design, the Abbe error can be reduced greatly by placing the stage center, grating ruler and displacement measurement centerline on the same line with grating reading head. The driving travel of nanopositioning stage is 150mm, and driving resolution is 1nm. The designing method introduced gives a scientific method and practical reference for the development of z-axis driving control system.

Abstract: The researchers and scientists have concluded that material dynamic fracture properties must be considered during the design stage of the modern structure. The dynamic stress intensity factor is very important in understanding of material dynamic behavior. Keeping in view the importance of the materials dynamic stress intensity factor: an efficient and reliable numerical-analytical procedure is developed for calculation of dynamic stress intensity factor. For this, three-dimensional model of a Modified Hopkinson Pressure Bar (MHPB) and a specimen is modeled and analyzed with the ANSYS software. Transient dynamic analysis technique is used for simulation of load-variations as a function of time. As an output of analysis, values of load point displacement and Crack Mouth Opening Displacement (CMOD) are obtained. These values are substituted into two different analytical formulas for calculation of a dynamic stress intensity factor. The results obtained are compared with previous published results, and a good agreement is found.

Abstract: Pipe-jacking method has been widely used in municipal engineering for its relatively simpler equipment and lower environment impacts. Since intact sections were used in traditional pipes, their application is restrained by transportation when the diameter is too large. A split prefabricated pipe-jacking structure design method is proposed in this paper. The traditional intact pipe section is split into several segments for assembling in the construction site, which can solve the transportation and stocking problem.

Abstract: Micromechanical silicon resonant accelerometer can easily realize high-accuracy measurement by taking the digital signal as the output. Thus, this accelerometer has become popular in the field of micromechanical accelerometer. One-mass accelerometer with differential structure has blind area in measuring, and to overcome this deficiency, a new structure without mechanical coupling is designed. This new structure can cut off coupling channels by isolating the mass, and vibration decoupling between two resonators can be achieved structurally. Furthermore, the scale factor of the designed accelerometer is as high as 295 Hz/g. This finding indicates that this accelerometer has high mechanical sensitivity, which reduces the difficulty of follow-up testing.

Abstract: The theory of gait is one of walking ways which is efficient, fast and stable in a variety of industrial robots, offering a structure of climbing robots in a way of gait and climbing with the gait motion in paper. Through the results of analysis by various industrial software, the presented structure of climbing robots which is composed of two terminal parts and two robot arms that is the part of pedestal and climbing mechanism. In the process of climbing, realizing gripping, Swing work, turning work, an orderly motion and get to the aimed place finally through alternate between the upper and lower part of the body by the control of SCM. The presented method has not only improved many problems like complicated climbing structure, controlling rough, slow-motion and unable thronging obstacles, but also accomplished the subsequent operations like tools delivering, pole testing, clearing, maintenance work, furthermore, there has more comprehensive benefits.