Full-Field Strain Measurement and Identification of Composites Moduli at High Strain Rate with the Virtual Fields Method
Full-Field Strain Measurement and Identification of Composites Moduli at High Strain Rate with the Virtual Fields Method
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DOI：
10.1007/s11340-010-9433-4
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发表时间：
2011-04-01
影响因子：
2.4
通讯作者：
Wisnom, M. R.
中科院分区：
文献类型：
--
作者：
Moulart, R.;Pierron, F.;Wisnom, M. R.
本文利用分离式Hopkinson压杆装置对高应变率加载下的玻璃/环氧复合材料拉伸试件进行了全场应变测量，并对其力学性能进行了鉴定。首先，介绍了所采用的方法：描述了包括超高速摄像机在内的装置，以及获得相关位移图的实验过程。然后讨论了两个力学试验的不同全场结果，包括位移、应变和加速度图。本文的最后部分介绍了利用虚拟场法，仅使用实际应变和加速度图(不考虑外力)识别这种动力情况下的刚度的原始过程。计算结果为准各向同性玻璃-环氧层压板的杨氏模量和泊松比提供了很有希望的取值。根据模数和应变重建的载荷与读数相比要好得多。
The present paper deals with full-field strain measurement on glass/epoxy composite tensile specimens submitted to high strain rate loading through a split Hopkinson pressure bar (SHPB) device and with the identification of their mechanical properties. First, the adopted methodology is presented: the device, including an Ultra-High Speed camera, and the experimental procedure to obtain relevant displacement maps are described. The different full-field results including displacement, strain and acceleration maps for two mechanical tests are then addressed. The last part of the paper deals with an original procedure to identify stiffnesses on this dynamic case only using the actual strain and acceleration maps (without the applied force) by using the Virtual Fields Method. The results provide very promising values of Young's modulus and Poisson's ratio on a quasi-isotropic glass-epoxy laminate. The load reconstructed from the moduli and strains compares favourably with that from the readings.