Advanced Materials Research Vols. 690-693

Abstract: The general method for strengthening the surface hardness is known to be heat treatment by means of the laser. Generally, the smaller and the lighter component is hopefully used for parts of machine or complicate structure. Hence, Instead of a heavy structure, a thin panel with sub structure or engraving the grooves or waving on that is used. It is noted well that those processes make an original structure strengthened. Therefore it is expected that the thin plate panel can be much more strengthened and stable through processing of the metal surface by laser beam irradiation. Through this research, it would be explained empirically how the hardness be changed and mechanical characteristic changed by width and depth of groove by laser affect. As of conclusions, the structural characteristics of a thin plate being strengthened locally by laser irradiation will be presented in comparison with the results obtained from FEA analysis

Abstract: Variable airship is an important research direction because it can overcome the difficulties in climbing phase caused by huge volume, and can also solve the problem of insufficient strength. The requirements of variation bring significant challenges for the airship structural design. In this paper, a radial variation mechanism was proposed based on an existing airship. The mechanism can achieve a continuous variation of the cross-sectional area from 100 to 7.2 percent. The airship structure was analyzed using the finite element method to make sure the airship has a high safety margin in various conditions.

Abstract: Autonomous underwater vehicle (AUV) is one of the current research hotspots in the field of robotics. It has abroad application prospect in the oceanographic survey, resource exploration and military fields. The AUV presented in this paper is mainly used for investigating the deep water oil and gas resources and works in underwater 3000 meters. It carries a series of measuring equipment, such as battery, sensors and pressure-resistant cabins, to engage in exploration tasks. When the AUV is lifted in water or in air, the loads acted on the main frame of AUV are different. In order to realize lightweight design and save buoyancy within the allowable range of the material strength, this paper puts forward a novel ladder type construction with two longitudinal beams and five crossbeams made of stainless steel, and analyzes the forces sustained by the main frame when lifted. Compared with traditional aluminum welding structure frames, the advantages of the trapezoid frame of the deep water AUV are as follows: large effective capacity, strong bearing capability and convenient maintenance. At the same time, using GRP hulls can improve the total structural strength significantly. The validity of the design and analyze is verified by recent at-sea trails.

Abstract: MAN Diesel’s 6S50MC-C two-stroke marine diesel engine is researched in this paper. The intensity under the effect of thermal load, mechanical load and coupled loads are analyzed. As the boundary conditions of the temperature field distribution, the mean temperature and the mean heat transfer coefficient are calculated firstly. Based on the temperature field, the thermal intensity is obtained in ANSYS. Then the study analyzes the stress and the strain distribution when the mechanical load and the coupled loads are applied. Through the analysis of different loads, the maximum stress is 696MPa in thermal load, 191MPa in mechanical load and 659MPa in coupled loads. The maximum deformation is 1.011mm in thermal load, 0.147mm in mechanical and 1.022mm in coupled loads. The intensity meets the design requirement. The stress concentration and the deformation of the piston crown mainly are generated by the thermal load. To reduce the destructive effect of thermal, it requests enhancing cooling and warming up the main engine.

Abstract: There is little research about the stability of T-stub steel axial compression component at home and abroad, and it remains to further investigation. On the basis of taking initial bending and other factors into consideration, through theoretical analysis and finite element calculation, this paper studies the T-stub steel axial compression buckling behavior and carrying capacity mainly using three different cross-section and different lengths ZC cross-sectional specimens.

Abstract: A circular ring is often used in the engineering. There are many applications in the tunnels, subways, and down hole. The purpose of this paper is to obtain the theoretical and numerical solution of the deflection of the circular ring under action of a concentrated force. Adopting the method of numerical analysis and Castigliano’s theory, the max deflection and the 4th equivalent stress of ring are developed. The results of the research indicate that the deflection of ring is the linear function of the concentrated force which is in accord with the elasticity body assumptions, that is Hook’s law. The theoretical solution of the deflection of ring is almost the same as the numerical one of the ring. So it is feasible that the numerical model of the ring is used to analyze the deflection of the eccentric ring.

Abstract: Track measuring beam is the most important structure in the inspection car and the vibration characteristics of it affect the inspection results and the fatigue strength of the bogie frame. In this study, the bogie frame finite element model of a inspection car were constructed and the free mode, static strength, fatigue strength and harmonic response were analyzed. The influence of the track measuring beam installation on the local modes, static strength and fatigue strength of the bogie frame were investigated and the suggestion on the method to reduce the track measuring beam vibration and improve the inspection quality was proposed.

Abstract: To cope with global warming and environmental protection in recent years, the requirements for clean energy are enhancing, and the installation of wind power, as one of such energy, is increasing in various countries. Nevertheless, the connection of wind blades and support blades often break when wind turbine are running. To avoid such a problem in the design stage or the successive reinforcement through proper methods has become an urgent problem in engineering. Commercial software, Solidworks Simulation, is used for simulating stress distribution and the patch reinforcement design in this paper. The analyses show that the maximum stress of the original design not being reinforced with patches has exceeded the tensile strength of the material and result in the breaks and damage of the entire structure. Using composite patches to reinforce the interface of wind blades and the supportive structure could effectively reduce the maximum stress and the displacement of deformation. Moreover, patches could effectively reduce the maximum stress that the optimal reinforcement should take a larger fillet into account.

Abstract: Bucket wheel stacker-reclaimer is kind of a typical multi-rigid-body system. Its main steel structure consists of bucket wheel, forearm frame, column tower, balance frame and pull rod, etc. All components connected with each other basically by welding. And the integral structure can realize whole luffing motion and turning motion. Reclaiming arm, central bracket and pitch steel structure of counterweight arm are the structure of its core. This paper use ANSYS to create the simplified finite element model of the steel structure and analyze the distribution of loads in all types of conditions. Loading solving, then cloud picture of displacement and that of stress of the overall luffing mechanism was concluded, so as to check the carrying capacity and strength of the structure.

Abstract: One collapse tower of 110 kV transmission line was taken as an example and a finite element model for the coupled tower-line system was established for investigating the effects of the strong wind on the transmission tower and line. The result shows that the selected standard of material of some rod members is lower, and the area of their section is relatively small. Main legs present buckling instability because of being in compression under action of the strong wind, which leads to the collapse accident of the towers.