Padhye Nikhil, Parks David M, Slocum Alexander H, Trout Bernhardt L
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Rev Sci Instrum. 2016 Aug;87(8):085111. doi: 10.1063/1.4960172.
Symmetrically bonded thin and flexible T-peel specimens, when tested on vertical travel machines, can be subject to significant gravitational loading, with the associated asymmetry and mixed-mode failure during peeling. This can cause erroneously high experimental peel forces to be recorded which leads to uncertainty in estimating interfacial fracture toughness and failure mode. To overcome these issues, a mechanical test fixture has been designed, for use with vertical test machines, that supports the unpeeled portion of the test specimen and suppresses parasitic loads due to gravity from affecting the peel test. The mechanism, driven by the test machine cross-head, moves at one-half of the velocity of the cross-head such that the unpeeled portion always lies in the plane of the instantaneous center of motion. Several specimens such as bonded polymeric films, laminates, and commercial tapes were tested with and without the fixture, and the importance of the proposed T-peel procedure has been demonstrated.
对称粘结的薄而柔韧的T型剥离试样，在垂直行程机器上进行测试时，可能会受到显著的重力载荷影响，在剥离过程中会出现相关的不对称和混合模式失效。这可能导致错误地记录过高的实验剥离力，从而在估计界面断裂韧性和失效模式时产生不确定性。为了克服这些问题，设计了一种与垂直试验机配套使用的机械测试夹具，该夹具支撑试样的未剥离部分，并抑制重力引起的寄生载荷对剥离试验的影响。该机构由试验机十字头驱动，以十字头速度的一半移动，使得未剥离部分始终位于瞬时运动中心平面内。使用和不使用该夹具对几种试样进行了测试，如粘结聚合物薄膜、层压板和商业胶带，证明了所提出的T型剥离程序的重要性。
