The optimization of fire robot axle in axle size based on dynamic strength and material cost
The axle of robot always afford complex load in a high dynamic vibration, the statics strength cannot take enough safety factor, and a larger safety factor would waste the material cost. In this paper, a new optimization function which takes consideration to the dynamic strength and material cost is derived. The dynamic strength has been discussed, a dynamic simulation modle based on FEA has also been bulid, the simulation results showed the boundary conditions of the optimization, the relationship between dynamic strength and axle size which was highly nonlinear, was simplized as a approximated sine function. The material cost factor is simplified to the mess of the axle. And all the factors in the optimization plently funtion were normalized, and the 3D graphic of the funtion has been draw, the extremum point of the optimization function, which was the most appropriate sizes of the axle, was found by the Matlab.
An Application of MATLAB in Optimization Design of Parallel Robot Mechanism's Physical Dimension
To problems on optimization design of parallel robot mechanism's physical dimension, a method using MATLAB and its optimization toolbox instead of that the traditional programming is put forward. With its simple programming and easily modify ,the method can solve optimal value and has extensive prospects in application in this field.
Thermal incompatibility analysis of metal-ceramic systems based on flexural displacement data.
The feasibility of simple tests or analytical methods for prediction of residual stress states in metal-ceramic (MC) prostheses has not been demonstrated. Biomaterial metal-ceramic strips have been proposed to provide sensitive measures of transient and residual stress states through the measurement of midpoint deflection after cooling from the ceramic sintering temperature. The objective of this study was to apply the elastic-viscoelastic analogy to calculate transient and residual midpoint deflections in MC biomaterial strips and to compare these values with deflections measured with a beam-bending viscometer (BBV). Calculations and measurements were made for five MC systems that were found from a clinical study to be "thermally compatible" systems. Metal strips, 64 mm in length, 3 mm wide, and either 0.5 mm, 1.0 mm, or 2.0 mm in thickness, were veneered with four 0.25-mm thick layers of opaque porcelain. Midpoint deflection of the MC strips (ceramic oriented in the posterior position) was measured during cooling from an initial temperature of 700 degrees C. In general, the directions of the measured residual deflections did not agree with the "textbook" convention that negative deflections are associated with positive thermal contraction mismatch (alpha(M) - alpha(c) > 0) regardless of metal thickness. For a metal thickness of 0.5 mm, the residual midpoint deflection for all thermal contraction mismatch cases, except one, was positive (upward deflection) whereas the residual midpoint deflections were all negative when the metal thickness was increased to 1 or 2 mm, independent of the thermal contraction mismatch. The best agreement between calculated and measured values of residual midpoint deflection (+16 microns vs. +14 +/- 2.3 microns, respectively was obtained for MC biomaterial strips with a Ni-Cr alloy (0.5 mm thick) while the largest difference (+346 microns vs. +61 +/- 43.8 microns) was obtained for MC bimaterial strips with a Au-Pd allow (0.5 mm thick). In all but one case, changes in deflection direction as a function of metal thickness were correctly predicted by the viscoelastic analysis. The results of this study indicate that a viscoelastic model is useful for estimating thermal compatibility conditions of MC systems.