熔融沉积成型3D打印拉丝缺陷的正交实验研究

为了及时解决打印过程中的拉丝异常工况，提出基于振动信号的熔融沉积成型(FDM)3D打印拉丝缺陷正交分析方法. 开展单因素试验，对加速度振动传感器采集的信号进行时域分析，提取相关峭度、峰值因子和脉冲因子特征值，确定喷头温度、回抽距离、回抽速率和空驶速率4个打印参数与零件拉丝缺陷的关系. 在单因素试验的基础上进行四因素三水平正交试验，以提取的振动信号时域特征值为评价指标，通过极差与方差分析对试验数据进行分析. 试验结果表明，利用该方法可以对拉丝缺陷进行识别，其中在使用材料为PLA的情况下，回抽距离和喷头温度对零件拉丝缺陷的影响显著，空驶速率和回抽速率影响不显著，当喷头温度为190 ℃、回抽速率为50 mm/s、回抽距离为12 mm、空驶速度为50 mm/s时，打印模型的拉丝情况最好.

Orthogonal experiment of fused deposition molding 3D printing drawing defects

An orthogonal analysis method of fused deposition molding (FDM) 3D printing drawing defects based on vibration signals was proposed in order to solve the abnormal working conditions of wire drawing in the printing process in time. The single factor test was conducted, and the time domain analysis of the signal collected by the acceleration vibration sensor was conducted. The correlation kurtosis, peak factor and pulse factor eigenvalues were extracted to determine the relationship between the four printing parameters, namely, nozzle temperature, pullback distance, pullback rate, empty driving speed and drawing defects of the parts. The four-factor and three-level orthogonal test was conducted based on the single-factor test, and the extracted time-domain eigenvalues of vibration signals were taken as the evaluation index. The test data were analyzed by range and variance analysis. The test results show that the on-line monitoring method based on acceleration vibration sensor can identify the drawing defects very well. The drawing distance and nozzle temperature significantly affect the drawing defects when the used material is PLA, while the effects of empty driving speed and drawing speed are not significant. The wire drawing condition of the printing model is the best when the nozzle temperature is 190 ℃, the drawing speed is 50 mm/s, the drawing distance is 12 mm and the empty driving speed is 50 mm/s.