润滑与密封
潤滑與密封
윤활여밀봉
LUBRICATION ENGINEERING
2013年
8期
13-16
,共4页
三维表面%分形维数%分形布朗法%盒维数法%小波变换法
三維錶麵%分形維數%分形佈朗法%盒維數法%小波變換法
삼유표면%분형유수%분형포랑법%합유수법%소파변환법
three-dimensional surface%fractal dimension%fractal brown dimension%box-counting method%wavelet transform
利用二维表面形貌计算分形维数具有随意性和不确定性。采用分形布朗法、原始盒维数法、改进差分盒维数法和小波变换法计算标准三维曲面的分形维数值,并与标准值进行比较,得到误差较小的三维表面分形维数计算方法。计算结果表明:盒维数法计算结果误差最大,受采样点数量的限制,选择的尺度不能太大,只有在小尺度时,才具有较好的直线性;小波变换法误差较小,但计算复杂,且使用的滤波器不同结果也不同,因此选择合适的滤波器非常重要;分形布朗法直线性较好,误差也较小,误差基本在3%以内,是计算三维摩擦表面分形维数的合适方法。
利用二維錶麵形貌計算分形維數具有隨意性和不確定性。採用分形佈朗法、原始盒維數法、改進差分盒維數法和小波變換法計算標準三維麯麵的分形維數值,併與標準值進行比較,得到誤差較小的三維錶麵分形維數計算方法。計算結果錶明:盒維數法計算結果誤差最大,受採樣點數量的限製,選擇的呎度不能太大,隻有在小呎度時,纔具有較好的直線性;小波變換法誤差較小,但計算複雜,且使用的濾波器不同結果也不同,因此選擇閤適的濾波器非常重要;分形佈朗法直線性較好,誤差也較小,誤差基本在3%以內,是計算三維摩抆錶麵分形維數的閤適方法。
이용이유표면형모계산분형유수구유수의성화불학정성。채용분형포랑법、원시합유수법、개진차분합유수법화소파변환법계산표준삼유곡면적분형유수치,병여표준치진행비교,득도오차교소적삼유표면분형유수계산방법。계산결과표명:합유수법계산결과오차최대,수채양점수량적한제,선택적척도불능태대,지유재소척도시,재구유교호적직선성;소파변환법오차교소,단계산복잡,차사용적려파기불동결과야불동,인차선택합괄적려파기비상중요;분형포랑법직선성교호,오차야교소,오차기본재3%이내,시계산삼유마찰표면분형유수적합괄방법。
The calculation results of fractal dimension by the method based two-dimensional surface are uncertainty and randomness.Four kinds of three-dimensional calculation methods,Fractal Brown Act method,the original box dimension Act method,improved differential box-counting method and wavelet transform method were used respectively to calculate fractal dimension of the three-dimensional surface constructed with W-M function,and the calculation results were com-pared with the standard value of fractal dimension.The result shows that box-counting method has the largest error because of the restriction on the number of sampling points the calculation scale cannot be too large,therefore only in small scale it has good linearity.Wavelet Transform has little error,but the calculation is complex,and the filter influences the calcu-lation result severely,therefore it is crucial to choose a suitable filter.Fractal Brown Act method has better linearity and litter error which is less than 3%.Therefore Fractal Brown Act is a suitable method to calculate the 3D fractal dimension of friction surface.