摘要
建立高精度的载荷模型是飞行载荷测量的关键。传统的载荷模型采用多元线性回归建立,确定载荷与应变响应的关系时,所需样本数量大,载荷标定工况数量要多于应变电桥数量,且要分析弯矩、剪力、扭矩、应变电桥之间的相关性。针对这些问题,提出了一种飞行载荷测量建模的新方法——响应叠加拟合法。新方法不需要传统的载荷方程,而是采用较少的若干组地面标定工况的电桥响应为基向量,以飞行状态下的电桥响应为目标向量,直接把飞行响应和地面响应数据关联起来,通过最小二乘法确定飞行和地面数据之间最优的拟合模型,再根据拟合系数叠加地面标定载荷间接求得飞行载荷。以某型机机翼载荷标定试验为例,用新方法建立了机翼根部的载荷模型,采用多区域协调加载工况进行了验证分析,得到弯矩和剪力的最大误差都在3%以内,表明响应叠加拟合法可作为建立飞行载荷测量模型的一种可靠、高效的方法。
The establishment of a high precision load model is the key to flight load measurement. The traditional load model is established by multiple linear regression. When the relationship between load and strain response is being determined, the number of required samples is large and the number of load calibration conditions is more than the number of strain bridges, and the analysis of correlation between bending moment, shear force and torque should be done. Aiming at these problems, a new method of flight load measurement modeling is proposed: response superposition method. The new method does not require the traditional load equation, but uses a small number of groups of ground calibration conditions of the bridge response as the base vector, and the bridge in flight response as the target vector, then directly associates the flight response with the ground response. The least squares method is used to determine the optimal fitting model between flight and ground data, and the flight load is obtained indirectly by superimposing the ground calibration load according to the fitting coefficient. Taking a certain wing load calibration test as an example, the load model of the wing root is established by using the new method. The maximum error of bending moments and shear forces are less than 3%, which indicates that the response-superposition-fitting method can be used as a reliable and efficient method to establish the model of flight load measurement.
出处
《应用力学学报》
CAS
CSCD
北大核心
2018年第1期22-27,共6页
Chinese Journal of Applied Mechanics
关键词
飞行载荷测量
载荷标定
载荷模型
响应叠加
最小二乘法
flight load measurement
load calibration
load model
response superposition
least squares
