Nielsen P M, Hunter P J, Smaill B H
Department of Theoretical and Applied Mechanics, School of Engineering, University of Auckland, New Zealand.
J Biomech Eng. 1991 Aug;113(3):295-300. doi: 10.1115/1.2894887.
A testing facility for measuring the biaxial mechanical properties of highly deformable membranes is described. Forces are applied, via strain-gauge force transducers, to four points on each side of an initially square 12 to 25 mm membrane sample to produce biaxial extensions of up to 80 percent of undeformed length. Strain is estimated from the displacement of markers bounding a 1 to 2 mm central square. The accuracy of stress and strain field measurements has been assessed by finite element analysis of a biaxially-loaded isotropic elastic membrane. Major advantages of the present system over those previously described in the literature are that 1) sample mounting procedures are simplified, 2) there is provision for independent adjustment of stress field uniformity and measurement of the applied point forces and 3) faster strain rates can be imposed on the relatively small samples tested.
本文介绍了一种用于测量高变形性膜双轴力学性能的测试设备。通过应变片力传感器，在初始为正方形的12至25毫米膜样品的每一侧的四个点上施加力，以产生高达未变形长度80%的双轴伸长。应变是根据围绕1至2毫米中心正方形的标记的位移来估算的。通过对双轴加载的各向同性弹性膜进行有限元分析，评估了应力和应变场测量的准确性。与文献中先前描述的系统相比，本系统的主要优点是：1）简化了样品安装程序；2）可以独立调节应力场均匀性并测量施加的点力；3）对于所测试的相对较小的样品，可以施加更快的应变速率。
