Measurements with digital image correlation of normal and tangential contact stiffness for ground Ti-6Al-4V interfaces suggest a linear relationship between normal contact stiffness and normal load and a linear relationship between tangential contact stiffness and tangential load. The normal contact stiffness for these surfaces is observed approximately to be inversely proportional to an equivalent surface roughness parameter, defined for two surfaces in contact. The ratio of the tangential contact stiffness to the normal contact stiffness at beginning of a load step is seen to be given approximately by the Mindlin ratio. A simple empirical model is proposed to estimate both normal and tangential contact stiffness at different loads for ground Ti-6Al-4V surfaces of known surface roughness and coefficient of friction.

Experimental images and load data were analysed with Digital Image Correlation using DaVis StrainMaster software. This was post-processed with MATLAB.

Summary

Raw image and load data are provided for all the tests. Each test consists of normal loading, tangential loading, and normal unloading sections. The measured pixel length for each test is provided. The data from digital image correlation (DIC) obtained from the raw images are provided. These are processed with MATLAB scripts. Further information can be obtained from the manuscript. 

Details

1. ‘RawImageAndLoad’ folder:

The raw experimental images and load data corresponding to each test section is provided in respective folders. The measured pixel length for each test is provided also.

2. 'DIC_Data' folder:

Raw images were processed by DIC software (DaVis StrainMaster) for each test section. The output files from StrainMaster alongside a load data file and DIC settings information file are provided in respective folders for each test section.  

3. 'Matlab_FinalProcessing' folder:

The MATLAB codes used to process the DIC Data for each test section are provided, in respective folders 

3.1       For processing normal loading and unloading test sections run scripts with prefixes A,B,C,D,E and F (in this order), within the respective folder.

The first script 'A_LoopFiles' will ask for a name for the test and the location of the DIC data for that test section. Provide the relevant folder found in 'DIC_Data' folder.

3.2       For processing tangential loading test sections. Run scripts with prefixes A,B1,B2,B3, C1,C2, and C3 (in this order), in the respective folder.

The first script 'A_LoopFiles' will ask for a name for the test and the folder location of the DIC data for that test section. Provide the relevant folder found in 'DIC_Data' folder.