Applied Mechanics and Materials Vols. 380-384

Abstract: Structure analysis is a vital link while designing aircraft assembly fixtures. ANSYS software is applied to analyze the structure of an aircraft assembly fixture based on a general method proposed in this paper. Firstly, a frame-type riveting assembly fixture is modeled, the static load and the boundary condition is preset according to the requirement of finite element analysis. Secondly, the static stiffness and strength is calculated considered both the condition with and without working load. Finally, the analysis and optimization process is conducted. The effectiveness and feasibility of this method has been proved combined with the simulation result and the reality test. The method can be applied to other aircraft assembly fixture when taking finite element analysis, thus it has the application and popularization value.

Abstract: Electric scissor aerial work platform generally uses hydraulic cylinder to lift. The decline solenoid valve is an important part of the entire hydraulic system, which usually installed in the bottom of the hydraulic cylinder. The main function is locking hydraulic cylinder to prevent the platform sinking due to its weight, protect workers safety. This paper first introduces its structure and working principle, and then does the experiments such as resistance pollutants, leakage, and a comprehensive analysis of the decline in the performance of the solenoid valve.

Abstract: In this paper, with a 92,500 ton bulk-carrier being mainly taken as an example, the preparing design of launching processing scheme on the horizontal berth is discussed. Calculation of needed hulling force and strength examination of hoisting pad are done, and then the structural strength of hoisting pads and their stiffening structures are analyzed with the aid of finite element technique. Once the total assembly of hull is completed on the berth, the launching weight should be calculated and proper number of box-beams should be determined. Sliding frictional media used between box-beams and slipping-rails should be selected, and according to combined frictional coefficient, the needed pulling force by which the hull may be hoisted forward securely should be fixed. In order to assure the safety of ship in the period of launching, strength examination calculating for hoisting pads and stiffening members should be done by means of finite element method as soon as their types and assembling positions are determined, so that the strength of hoisting pads and stiffening structures should be able to meet the requirements. Owing to that this ship having being successfully launched, the reliability and usability stated in this paper have being verified. Therefore, it is of quite value to be referred in technical analysis for launching on the horizontal slipway.

Abstract: When comparing with ship construction within newly-built docks or on tilting slipways, ship constructing on the flat earth method can be said to be a new ship-building technique by which ship is built on a platform and launched with the aid of floating-dock or barge. Some obvious advantages of this technique are such as less investment in basic facilities, low production cost, high production efficiency, wide applicability of ship types, ability to overcome the bottle-neck effect of berths and docks. In this paper, a bulk-carrier being taken as an example, the design of launching processing scheme on the horizontal shipway includes calculation of launching weight and determination of hoisting force during the whole towing period. The whole towing process of hull can be divided into three stages, the first is from the static state to the moment of beginning to move, the second is from the initial position of movement to the front of slipway onto which the hull is predicted to be pulled, and the third is from the front of slipway to the designated position on the floating dock. Subsequently, after the hull being sealed and positioned correctly, the floating dock for launching may be towed to deeper water zone and the hull can be buoyed up on the water surface, and the whole launching process can be completed. From the research, the conclusion is made that the launching technique of this paper is available and feasible. Especially, this paper is the initial application of this method on the 15000t launching ship home and has the epoch-making sense.

Abstract: Aircraft in flight, such as supercooled water droplets encountered icing conditions suitable for the external environment, the relevant parts of the body will freeze, making the aircraft's aerodynamic performance deterioration, severe endanger flight safety, in addition, the aircraft parked in the open winter months , there will be icing, you need to clean up before takeoff. We should grasp the mechanism of aircraft icing, environmental factors and easy to freeze parts of the body. This paper presents a simulation using the wind tunnel icing device icing wind tunnel simulations can reproduce the real situation of aircraft icing, for guiding practice and got good results.

Abstract: This paper presents a full-car model of vehicle fitted with roll resistant specific HIS system in order to research the coordination of the main modals of sprung mass. Based on the transfer matrix method and state space method, the mechanical and hydraulic coupled multi-body dynamic equation is derived. The eigenvalue and eigenvector is solved by eigenvalue iteration identification method of frequency-dependent characteristic. By discussing the characteristic of the damping components which are the dominant parameters of the coupled system, an innovative design approach of damping components of the HIS system is proposed. Finally, comparison of vehicle vibration is carried out between vehicle with traditional suspension and that fitted with roll resistant specific HIS system. The obtained result indicates that with the proposed design approach of damping components, the roll resistant specific HIS system can promote the capacity of anti-rollover specific observably with reasonable comfort performance.

Abstract: With the development of high-speed railway in China, CRH is widely used in railway transportation. Traditional method of braking distance calculation is not suitable for CRH. In this paper, a more accurate brake distance of CRH locomotive has been calculated by using the calculus form of the kinematics formulas and verified by real data. Compared with existing data, the authenticity of this calculation is notable. The result is of real value for the researches about high speed train and it makes the control of CRH more accurate.

Abstract: Based on characteristic of water jet, there are two important factors to product the thrust. One factor is pump speed and the other is the nozzle diameter. So, The significant optimization be required in order to overcome the existing water jet propulsion problem. In this paper, the water jet propulsion system model be studied at first, and then pump and nozzle optimization be discussed. At last, the result shows that the thrust of water jet by controlling the nozzle diameter size and pump speed.

Abstract: According to the large beam reheating furnace widely used in metallurgy area, the mathematical model was built basing on the heat transfer. Considering the uncertain and nonlinear characteristics existing in the system, the robust stabilization problem of the system is investigated basing on Lyapunov stability theory and linear matrix inequality (LMI) method. The robust controller is designed. A numerical example and its simulation results are given.

Abstract: A method to predict pitch and roll damping derivatives of aircraft geometries with fins using an unsteady RANS solver is presented. A three-dimensional structured RANS solver based on the arbitrary Lagrangian-Eulerian (ALE) formulation with a dynamically deforming mesh algorithm is used and validated with the wind tunnel and ballistic range data available in the literature. Roll and pitch damping derivatives are calculated from load history of the unsteady flow around the model. A standard research configuration, known as the Basic Finner, is studied under forced pitching and rolling conditions. Pitching and rolling motions with oscillation are analyzed at supersonic Mach numbers ranging from 1.5 to 2.5. Predicted results showed good agreement with the available wind tunnel data.