非定向有机玻璃拉伸断口形貌与拉伸温度相关性分析

Correlation analysis between tensile fracture morphology and tensile temperature of non-oriented acrylic sheet

为探究非定向有机玻璃断口定量表征方法及其断口形貌参数与拉伸温度的相关性,以航空有机玻璃YB-2为研究对象,首先采用体视显微镜和三维激光扫描仪测量了不同拉伸温度下的断口雾状区尺寸和表面粗糙度均值Ra,其次通过扫描电镜-盒维数法测算了断口雾状区的分形维数均值D,最后通过两个假设推算了有机玻璃断裂形成雾状区时消耗的能量,并与断口雾状区的分形维数进行联系。结果得出:当拉伸速率一定时,拉伸温度由-55℃提升至60℃,断口雾状区的尺寸J3从1.257 mm升高至4.978 mm,Ra从0.517μm降低到0.330μm,D从1.357升高至1.579,拉伸温度分别与断口雾状区尺寸、表面粗糙度、分形维数的拟合曲线的拟合度因子均高于0.9,拟合程度较高。研究表明:有机玻璃拉伸断口的形貌参数与其断裂条件存在一定的相关性,雾状区形成时消耗的能量与其分形维数呈正相关关系,该研究结果可为有机玻璃断口定量分析奠定一定的基础。

In order to explore the quantitative characterization method of non-oriented acrylic sheet fracture and the correlation between the fracture morphology of acrylic sheet and tensile temperature.The non-oriented acrylic sheet for aircraft was used as the research object.Firstly,the size and surface roughness of the mist region were measured by stereo microscope and 3 D Laster Scanner(LEXT).Secondly,the fracture was measured by box counting method.Finally,the energy consumed by the rupture of the acrylic sheet to form the mist zone was estimated by two hypotheses and was related to the fractal dimension of the fractured mist zone.The results show that when the stretching rate is constant,the stretching temperature is raised from-55℃to 60℃,the size of the fractured mist zone I3 is increased from 1.257 mm to 4.978 mm,and the surface roughness Ra is reduced from 0.517 μm to 0.330 μm,the fractal dimension D is increased from 1.357 to 1.579.The fitting degree factors of the fitting curves of the tensile temperature and the size,surface roughness and fractal dimension of the fracture foggy area are higher than 0.9,and there fitting degree of these curves are higher.Therefore,the morphological parameters of the tensile fracture of the acrylic sheet have a certain correlation with the fracture conditions,and the energy consumed in the formation of the mist region of the acrylic sheet is positively correlated with its fractal dimension.