Optimization of the passenger car body base structure in order to increase energy intensity in a side impact

The paper considers the possibility of increasing the level of passive safety of the vehicle by development of solutions for strengthening the base of the body. The method to achieve this goal was mathematical modeling using topology optimization modules (Topology Optimization) as well as topographic optimization of sheet bodies of Altair Inspire software and LS-DYNA explicit dynamics of ANSYS. A side impact against a pole defined by UN ECE 135 was selected as the loading mode to test the effectiveness of the strengthening a body base. Efficiency criteria were energy intensity, defined as the ratio of the system energy to the residual (plastic) deformation at the level of the center of the door, and the residual living space. Based on the optimization results, three variants of the strengthening elements arrangement were obtained, one of which was further strengthened with aluminum foam. A comparative assessment of the effectiveness of the considered strengthening options was performed using the simulation results. The most effective option (with transverse stampings and foam) allowed increasing energy intensity by 57.5%. The assessment of the residual living space was carried out, the cutting out of which turned out to be possible only by one strengthening option: with transverse stampings with foam.

Topological optimization of the roofing structure of a passenger vehicle to increase energy intensity in a side impact

This article considered the main issues of finding options for strengthening the roofing of the ve-hicle body based on topological optimization in order to meet the requirements of passive safety with a minimum mass. The method for achieving this goal was mathematical modeling using the Topology Optimization modules of the ANSYS software package and the explicit dynamics of LS-Dyna. In order to test the effectiveness of the reinforcements, the pillar side impact according to UNECE 135 “Uniform provisions concerning the approval of vehicles with regard to their perfor-mance in side impact on a pillar” was selected as the loading mode. The efficiency criterion was the energy intensity of the body, defined as the ratio of the energy of the system to the residual (plastic) deformation at the level of the center of the door. Based on the topological optimization, two vari-ants of the arrangement of the reinforcing elements, practically equivalent in efficiency, were ob-tained. For the most complete assessment of the influence of the parameters, several options for strengthening the roofing were considered: placement of steel reinforcing elements; placement of foam aluminum under the roof; combination of steel elements with filling their cavities with foam aluminum. Based on the simulation results, a comparative assessment of the effectiveness of the considered amplification options was carried out. The most effective were the options for reinforc-ing the roofing with channel-shaped beams and filling them with foam and the option for reinforc-ing the roofing with channel-shaped beams and diagonal bridges in them, causing it to increase compared to the original structure by 20.88 and 19.94%, respectively, but at the same time the mass of the first option is 42 kg less than the mass of the second.

Dynamic observation of X-ray Laue diffraction on single-crystal tungsten during pulsed heat load

The dynamics of the diffraction peak shape during pulsed heat load on mosaic single-crystal tungsten were measured at the `Plasma' scattering station on the eighth beamline of the VEPP-4 synchrotron radiation source at the Budker Institute of Nuclear Physics. The observed evolution of the diffraction peak shape agrees with theoretical predictions based on calculations of deformation caused by pulsed heating. Three clearly distinguishable stages of the diffraction-peak evolution were found, correlating with the evolution of temperature and deformation distributions. The residual plastic deformation increased with subsequent heating pulses.

Study the Relationship of Accumulation Residual Strain and the Loading Number of Completely Decomposed Granite and Cement Improved Soil

This paper based on the dynamic triaxial tests of completely decomposed granite samples of the Wuhan-Guangzhou passenger line to study the relation of the accumulated residual strain and the load times of completely decomposed granite and cement improved soil, and analyzes whether they meet the dynamic strength and cumulative cyclic deformation indicators and requirements of high-speed railway under vehicles load. High-speed driving when the subgrade generate residual plastic deformation. Residual plastic deformation of the continuous development will inevitably lead to the deterioration of the road, such as cracks, jack mud, uneven subsidence and long-term slow subsidence of the roadbed. Therefore, by studying the dynamic strength and the size of the dynamic stress of different parts of subgrade embankment to determine the appropriate filling parts of filler and control the final dynamic stress level of the roadbed at a reasonable range in order to ensure lines in good condition in the design life.