Abstract: Adopting concentric canister launchers (CCL), high temperature and high pressure environment of CCL is unfavorable for the missile launch. In addition to the gap between internal canister and external canister, injecting water for cooling are the main factor of impact the canister flow field, CCL’s rough wall is also a very important influence factor. In this paper, under the two working conditions of rough wall and smooth wall, use dynamic layering manner of moving mesh update method to simulate concentric canister missile launch process. The results reveal that rough wall has a great influence for pressure of concentric canister internal flow field, but the least influence for temperature. In practical engineering applications, need smooth surface material for smooth flow field exhaust when manufacturing concentric cylinder, but the non-concentric canister manufacturing of missile cold-launch canister, retain the rough wall can increase the pressure of the missile launch, this is conducive to missile launch, and also saves manufacturing costs, reduces processing procedures.
Abstract: Along with the rapid development of construction industry, tower crane becomes the indispensable machine in building trade. Using a simple and effective modeling method for sling is a crucial step in the analysis of tower crane. The 6 different models for sling of the tower crane were established by using the finite segment method of ADAMS in this paper, and the simulation of the sling based on applied mechanics was done. The conclusion was drew that in the modeling of sling, a rigid rod can substitute for sling, in the case that the resistance and axial stretching deformation of the sling were neglected. So a simple modeling method was given for sling of tower crane in a special case.
Abstract: With the rapid development and popularization of frequency converter, the application of frequency converter used in the main transmission of milling machine could realize stepless speed regulation. Thus the optimal cutting speed is achieved. In this paper, a new design of spindle box of horizontal milling machine is proposed. The cutting force of face milling is analyzed deeply. The applied mechanics analysis of transmission shaft is also discussed in detail. And the milling machine structure is simplified as well.
Abstract: The different mechanical property determines the difference on cracking behavior between GFRP/steel wire composite rebar reinforced concrete beams and steel rebar reinforced concrete beams according to cracking mechanics. In order to study the cracking behavior of concrete beams reinforced with GFRP/ steel wire composite rebar, five simply-supported beams were tested under three-point static load. The test variables were beam section size and concrete cover depth. Based on analysis on the test results, the calculation methods of cracking capacity and maximum crack width were proposed, and the limit value of crack width was suggested.
Abstract: Through the closed loop system response curve of the approximate treatment and the concept of dominant pole, combined with the root track analysis, the most similar to the open loop system model in applied mechanics is obtained. In the process of the closed-loop system model, the friction and gear clearance is considered for manufacturing system. The path planning is proposed for wheeled mobile robots
Abstract: In actual production, able to predict that their products performance can meet the requirements of the national standard, whether or not to meet the pursuit of enterprise product high standard quality requirements. To solve this problem, in the plate production site collection plate large amount of measured data in sheet metal production, main technological parameters of field measurement, and at the same time on the production of sheet metal plate products the main mechanical properties experimental determination.
Abstract: Fatigue damage caused by alternating operational stresses in terms of temperature or pressure change is the one of important damage mechanisms in the nuclear power plants (NPPs). Although components important to safety were designed to withstand the fatigue damage, cumulative usage factor (CUF) at some locations can exceed the design limit beyond the design life. So, it is important to monitor the fatigue damage of major components during the long term operation. To evaluate fatigue damage, the Green’s function approach has been generally used. In this approach, thermal stresses can be directly calculated from the convolution integration on the coolant temperature history and Green’s function. And, Green’s function is defined as a stress variation at the arbitrary point when the coolant temperature is increased as a unit step. However, this approach cannot be applied to the fatigue analysis using temperature-dependent material properties because it is assumed that the system is linear. In this paper, the modified Green’s function approach considering temperature-dependent material properties is proposed by using neural network. To verify the modified Green’s function method, thermal stresses by the proposed method are compared with those by finite element analysis (FEA) at the transition wall of reactor pressure vessel and the analysis results between two methods are well agreed. Finally, it is anticipated that more precise fatigue evaluation is performed by using the proposed method.
Abstract: In this paper, the peakons and bifurcations in a generalized Camassa-Holm equation are studied by using the bifurcation method and qualitative theory of dynamical systems. First, the averaged equation is obtained by introducing linear transform and traveling wave transform to the generalized Camassa-Holm equation. Then, we applied the bifurcation theory of planar dynamical system and maple software to investigate the averaged equation. The phase portrait of the system under a parameter condition is obtained. Finally, we get the peakons from the limit of general single solitary wave solution.
Abstract: In this paper, we investigate a class of three dimensional nonlinear dynamical systems whose unperturbed systems have a family of periodic orbits. Firstly, we establish the moving Frenet Frame on these closed orbits. Secondly, the successor functions are defined by the orbits which go through the normal plane. Finally, by judging the existence of solutions of the equations obtained from the Successor functions, we obtain the necessary condition for the existence of periodic solutions of these three dimensional nonlinear dynamical systems. The result has important significance for the basic research of applied mechanics.