超大构件机加工中徐变补偿的定位拟合法

Fitting Positioning Method With Creep Compensation in Large Component Machining

通过在机加工生产线外测量特征点的方法得到混凝土超大构件的毛坯模型,采用龄期调整有效模量法计算超大构件的混凝土徐变,在最小二乘定位拟合算法基础上设计徐变补偿定位拟合算法,以得到机加工时的精确毛坯模型.机加工时只需再次测量少量特征点,并利用徐变补偿算法得到的构件毛坯模型进行匹配,即可求得机加工模型.对某预应力混凝土轨道梁机加工的研究结果表明,徐变补偿的定位拟合法的拟合精度与在机加工生产线内再次测量所有特征点所得的拟合精度非常接近.

The blank model of a large-scale concrete component was established by measuring characteristic points outside the machining line, and then through age-adjusted effective modulus method, the concrete creep was calculated. Based on fitting algorithm of least-squares estimation in target location, the position fitting algorithm for creep compensation was given to obtain the accurate blank model for machining. When machining,just a few characteristic points are needed to match with component blank model based on creep compensation algorithm,and then the machining model can be built. The machining results about a prestressed concrete track girder show that the fitting precision calculated by position fitting algorithm is very close to that by remeasuring all characteristic points of machining line.