Influence Of Rollers Research Articles

Determination of residual stresses during flaring of heat exchange tubes

The calculation of residual stresses in the attachment points of heat-exchange tubes in tube sheets during flaring is proposed, taking into account the peculiarities of axial movement of the spindle and local deformation of the tube under the influence of rollers. The calculation was based on the theory of continuity of a continuous medium and experimental data. Keywords: flaring, pipe, tube sheet, stress, deformation, torque. mironova_lub@mail.ru

Analysis of the Influence of Segmented Rollers on Slab Bulge Deformation

The bulge deformation of the continuous casting slab must be controlled in order to improve the slab quality. In this study, a coupled three-dimensional thermomechanical model is suggested based on dynamic contact between the slab and the rollers, so as to investigate the influence of the rollers in reducing slab bulge deformation. Moreover, the rigid casting rollers in this model are replaced by elastic casting rollers in order to improve the calculation accuracy. Further, the influence of two-segment and three-segment rollers on the slab bulge deformation is systematically studied. The results indicate that the bulge deformation of the slab increased by 74.3% when elastic casting rollers were adopted instead of rigid casting rollers. This deformation was reduced by 29.7% when three-segment rollers were used instead of two-segment rollers. Moreover, the influence of the roller spacing and the roller diameter of the segmented roller on the deformation was studied in detail. In order to achieve the purpose of controlling the bulge deformation, improved segmented roller spacing and diameter were proposed, leading to a 75.4% reduction in the bulge deformation.

AFM-based local thermal analysis is a suitable tool to characterize the impact of different grinding techniques on sucrose surface properties

Influence of roller and ball mill grinding technology applied for sucrose particles in a lipophilic suspension was investigated considering both particle properties and suspension's flow behavior. Especially particle surfaces after grinding were analyzed using a novel approach by combining atomic force microscopy (AFM) and AFM-local thermal analysis (AFM-LTA). This technique is able to characterize local distributions of different surface states on sucrose particles in nano- and microscale by determining local softening temperatures. For the first time, it was possible to demonstrate on molecular level that applied grinding technologies resulted in different surface characteristics with respect to adhesion forces and state of sucrose using AFM-LTA. Differences in flow behavior despite same particle size distributions and solid contents were traced back to the distribution of crystalline and amorphous areas on sucrose particle surfaces.

Influence of Roller on Tooth Height of Internal Spline Formed by Spin-Forming

Spin-forming of part with internal tooth is a new technology of the near-net forming in gear manufacturing field. And the main purpose of the parts spin-forming is to shape teeth on the internal surface of blank. In order to improve the forming quality of internal tooth, the effect of roller on tooth height of spline was investigated by processing experiments and finite element simulation. The result indicates that, for full-radius roller, a large nose radius has also witnessed a discernible growth in spinning force and tooth height; considering the uniformity of tooth height distribution of spun part and decrease in forming force, the bio-conical roller is more suitable for this forming process