Dynamic Analysis and Design of Steel-Ball Grinding Machines Based on No-Slip Cases
Based on no-slip cases between steel balls and lapping discs while a horizontal grinding machine is working, the motion equations of the ball lapping are established and the law of motion is revealed by the MATLAB software. This paper shows that the difference of the trace spacing is reduced by increasing the disc diameter, which can make the trace distribution of the steel ball surface more uniform. In order that balls do not slip when rotary disc drives them to rotate, the ranges of the lapping pressure and lapping disc speed is deduced by using the dynamics analysis considering from the vertical trench surface and along the groove surface, respectively. Finally, this paper takes the selected material as an example to analyze the process parameters that affect the lapping curves, and explains the selection principles of alpha and beta when the trench has some bias, which can provide a reference to improve the quality of the steel balls surface.
Super grinding of steel ball and whet liquid
Through analysing the super grinding production method and the whet liquid performance, a technological process is improved and the steel ball quality is increased.
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.