No abstract

In extrusion stretch bending process, there are many factors which affect springback of the workpiece such as mechanical properties of the material, friction condition and process parameters. The springback of same batch of extrusion is different at same forming parameters because of the variation of the mechanical properties of the material and the friction condition. A method of intelligent control of springback in stretch bending process is proposed by using ANN(artificial neural networks). The online identification model of the mechanical properties of the material and friction coefficient and the online prediction control model of springback of workpiece in stretch bending process are established by using ANN ,which are trained by the data of analysis calculation. It realizes the intelligent control on springback of stretch bending to online identify the material properties and friction coefficient and predict springback and adjust process parameters dynamically through the whole process of stretch bending. The results from the experiment state that the intelligent control method can suit the variation of mechanical properties of material and friction condition and improve the geometry precision.

Immune algorithm is a set of computational systems inspired by the defense process of the biological immune system, and is widespread used in the combinatorial optimization problems. This paper describes an improved immune algorithm to solve the combinatorial optimization problems. The TSP problem is a typical application of the combinatorial optimization problems. The improved immune algorithm which based on the quantum principles is proposed for finding the optimal solutions to solve the TSP problem. In process of solving TSP problem, the quantum concept is used in initializing a population of quantum bit chromosomes. In the antibody’s updating, the general quantum rotation gate strategy and the dynamic adjusting angle mechanism are applied to accelerate convergence.According to the analysis of the experiment, the algorithm is not only feasible but also effective to solve TSP problem. It effectively relieves some disadvantages of the quantum and immune optimization.

To investigate the interaction mechanism of PVA on the surface of HA, the molecular dynamics simulation was applied to simulate and calculate the binding energy between PVA of different monomers and HA crystallographic planes (001), (100) and (110), and then the mechanical properties and radial distribution function of the PVA/HA(110) system were calculated and analyzed. The results show that HA (110) has the higher binding energy with PVA than that of HA (001) and (100). The binding energy and the Young’s modulus of HA(110)/PVA system increase with the rising of PVA monomer number at the same crystallographic plane in a certain range, however, the descending trend takes place while monomers number reaching a certain value. This change trend is relating to the effective contact between two single components. By calculating the pair correlation function of HA(110)/PVA, there is a strong interaction between HA crystallographic plane (110) and PVA, it is mainly derived from the hydrogen bonds between O atoms of PVA and H atoms in HA crystal, besides, the ionic bonds interactions existing between OaandCa.

The shallow basin-shaped aluminum sheet part had buckling defects after the bladder forming. Analysis the buckling defects’ mechanism, according to these, we proposed one step bladder forming process, used rolling leveler which could reduced the buckling height to level sheet before bladder forming, and made experiments to compare the structure effect of buckling height among the four kinds of die structure. The results showed that the one step bladder forming process is valid, and used the original die with sheet edge fold when it was bladder forming.