Numerical Simulation Study on Wear of Spur Gears under Dynamic Conditions

A numerical simulation model is proposed to predict the wear depth of gears,where Archard's wear equation and a nonlinear dynamic model are combined to establish a wear calculation model under dynamic conditions.The dynamic meshing force,determined by the non-linear dynamic model,and the sliding coefficient are used by Archard's wear equation to calculate the surface wear.Then the dynamic meshing force and sliding coefficient would be recalculated according to the surface wear state.After repeated iterations,the simulation results show that the peak and fluctuation of the meshing force increase first,then decrease,and eventually maintain stability during the process of wear.As for the distribution of wear depth,its fluctuation also increases first and then declines.Finally,the distribution of wear depth becomes V-shaped.Comparing the trends of the two factors,it is clear that the meshing force and wear depth are closely related.Moreover,the wear rate maintains a higher constant value first and then declines to a lower constant value.

Determination of Aspartame Content in Liquor by High Performance Liquid Chromatography

[Objectives]This study was conducted to establish a method for the determination of aspartame in liquor by high performance liquid chromatography.[Methods]The liquor samples having volumes fixed with ultrapure water were filtered by 0.22μm water phase,and then the content of aspartame in liquor was determined by high performance liquid chromatography using methanol(A)and ultrapure water(B)as mobile phase for isocratic elution.[Results]The results showed that a good linearity was obtained for the standard curve(R^(2)=99.98%)in the method,and its quantitative limit was 5.34 mg/kg.Its recovery was 91.26%,91.92%,and 90.55%,respectively.[Conclusions]The method has high sensitivity,high recovery and low quantitative limit,and it was a suitable method for the determination of aspartame in liquor.