Experimental data set for: A crack growth rate model with load history effects for mode I fatigue-driven delamination under multi-level block loading
This data repository includes the experimental data from multi-level block loading tests presented in the paper: "A crack growth rate model with load history effects for mode I fatigue-driven delamination under multi-level block loading" as published in International Journal of Fatigue by the same authors. Fatigue experiments are conducted on glass/epoxy double cantilever beam (DCB) specimens subjected to pure bending moments in mode I crack opening. The specimens are subjected to variable amplitude (VA) block loading, i.e. a block loading spectrum that consists of multiple constant amplitude (CA) load blocks with different amplitude and mean values. The fatigue experiments are conducted with real-time control of the applied energy release rate (ERR). Two repetitions of the multi-level block loading experiment is provided here. The data repository includes .txt files with the following data from the multi-level block loading tests: * The number of load cycles, N. * The maximum applied energy release rate, Gmax, normalised with respect to the material's critical energy release rate, Gc, Gmax/Gc. * Load block identifier. * The average crack length across the specimen width, a [mm]. * The crack growth rate, da/dN [mm/cyc]. * The crack growth rate as measured in the experiment, da/dN_VA, normalised with respect to the crack growth rate measured under constant amplitude loading, da/dN_CA. Note the crack growth rate, da/dN, is computed for every data point in the (N,a)-data set by fitting a linear function to all data points within a moving fitting window that has been centered around the data point of interest. For multi-level block loading spectra, the crack growth rate is computed separately for every load block. The crack growth rate data provided here are computed with a fitting window size of Delta_N=2000 load cycles and Delta_a=2 mm. The crack length is measured using an automated digital-image based technique for tracking of crack fronts in translucent materials. For this purpose, the top surface of the DCB specimen is camera recorded during the fatigue tests. Images are acquired at a predefined cycle increment, which controls the temporal resolution of the crack length measurements. The process is fully automated and continuous without pausing/interrupting the cyclic test. Find more information on the test procedure and experimental data in the article "A crack growth rate model with load history effects for mode I fatigue-driven delamination under multi-level block loading"