Design and optimization of drawing surface and FE analysis forthe front side panel of autobody

The drawing process of the front side panel of autobody is simulated by using the finite element software, Dynaform. The drawing surface is designed, focusing on the optimization of the addendum and the drawbead layout. By comparing the stress/strain conditions and the FLD in two types of addendum (stepped and slope) and three types of drawbead layout (closed, discontinuous and oblique drawbead), the slope addendum is chosen as the optimized addendum and the oblique drawbead is chosen as the optimized drawbead layout. The simulation results show the material flow in the corner and the quality of the part can be improved effectively with the optimized drawing surface. The optimized parameters are employed in production and acceptable quality parts are produced. Therefore, the optimized drawing surface is verified to be effective.     

Analysis of Out of plane Stability for Planar Tubular Truss with Mixed Finite Elements Method

Out of plane instability is usually one of the failures for planar tubular truss without out of plane braces under ultimate load. The mixed model of beam and shell elements, with the characteristics of high solving precision and less elements, can undertake overall stability analysis as well as the joints mechanic property when solving the issue of out of plane stability. Based on the principle of mixed finite element, nodes constraint equations at the interface between beam elements and shell elements were derived. And advices on the element division and solving method were proposed in order to avoid numerical difficulty in solving the mixed finite element equations. With the numerical solution and experimental test, it was found that the out of plane instability process can be expressed accurately with less time consuming by the proposed method and the proposed solution.      

Numerical Simulation for Dynamic Response of Large Space Cylindrical Reticulated Shell under Internal Explosion by Ritz POD Method

A numerical simulation test of the internal explosive loading on large space structure was carried out by employing algorithm ANSYS/LS DYNA.An appropriate model was established for calculating the dynamic responses of the large space cylindrical reticulated shell under inner blast loading based on the proof of correctness and reliability of the model and parameters selection.Combining the Ritz vibration mode superposition method with the Proper Orthogonal Decomposition (POD) method, the problems of spatiotemporal asynchrony of shock waveforms and pressure distributions on large space structure surface were solved and the calculation for dynamic response of large space structure was reduced and simplified.Furthermore, the numerical simulation of dynamic responses was carried out.And the influence of the ratio of rise to span and the explosive position on the dynamic responses of the structure was studied.It was found that the calculation model was suitable for the dynamic response analysis of the large space cylindrical reticulated shell under internal explosion and the cylindrical reticulated shells with bigger ratios of rise to span were stronger in the capacity of anti explosion.In general, the damages to the large space structure caused by eccentric blast shock waves were more serious than that caused by central explosion.And it was the most disadvantageous to the edge components of the structure.The more attention should be paid to the anti explosion capacity of the support areas and the edge components while designing the shells.     

Characteristic analysis and optimization design of dual-clutch transmission and double-turbine torque converter’s two-body flexible flywheel

Dual-clutch transmission and double-turbine torque converter’s flexible flywheel is the newly developed type which has applied the design of a two-body flexplate. Corresponding 3D modeling of this new type of flywheel has been constructed by virtue of the software Pro/Engineer. Further comparative analysis has been studied in terms of structural stress, modal, and harmonic by the finite element software ANSYS Workbench, Through all these studies, the simulation results show that two-body flexible is a kind of the structure has a better performance. On this basis, the shape of the flexplate in the flywheel has been optimized with different flexibility to meet the requirement of dynamic characteristics, the test verifies the correctness of analytical approach and the rationality of product structure. A feasible design and practical analytical approach has been brought up through this study.     

Numerical simulation of outburst prevention air door destruction by coal and gas outbursts

We explore the destruction of outburst prevention air doors by coal and gas outbursts using numerical simulation. The reflective overpressure when an outburst acts on doors is elucidated, and its formula is obtained. The destruction of outburst prevention wind doors by coal and gas outburst are simulated using ANSYS software based on data of wind door pressure obtained by similarity simulation experiment. The simulation results show that the weakest place of gate posts is where the wind tube is. Simulation results also show the first shock wave pressure that acts on an outburst prevention wind door is not the maximum one. Due to the effect of reflected overpressure, the outburst prevention wind door pressure will reach the maximum in several milliseconds. This finding is similar to the experiment result.     

New Monitoring and Assessment Method for the Joints of Steel and Concrete Connection in Large span Bridge

The joints of steel and concrete (JSC) is the key substructure to composite bridge, the method of condition monitoring and safety assessment were carried out for JSC with perfobond shear connectors (PBL) and local prestressed tendon in large span bridge. According to the damage mechanism of JSC, new monitoring parameters were proposed. The sensor location layout and the assessment thresholds of PBL were addressed with the consideration of the disadvantage influences of environment, load and concrete creep to local prestressed loss assessment and validated by the static load experiment. Compared the experimental results with field monitoring data, it was found that the new monitoring parameters and new assessment method were feasible and can be used as reference to the same type connectors in large span bridges.