In situ micro-XRCT data sets of an open-cell polyurethane foam sample under combined loading conditions (compression + torsion, tension)

This dataset contains eight micro X-ray Computed Tomography (micro-XRCT) scan data sets (projection, reconstructed, and binarized images, respectively) of the identical open-cell reticulated polyurethane (PUR) foam sample with 10 pores per inch under different loads. The initial diameter and length of the unloaded cylindrical sample were 50 mm and 46.5 mm. The sample was glued on two sample holders to apply compression, tension, and torsion, cf. Ruf & Steeb (2023). The sample was subjected to two load protocols, A and B. Load protocol A consisted of the following steps:
<ol>
<li>initial state: &#949 = 0.0; &#966 = 0.0 degree &#8594 scan "A_t0"</li>
<li>(i) twisting &#966 = 20.0 degree; (ii) compression &#949 = -0.2 &#8594 scan "A_t1"</li>
<li>(i) twisting &#966 = 0.0 degree; (ii) tension &#949 = 0.05 &#8594 scan "A_t2"</li>
<li>end state: &#949 = 0.0; &#966 = 0.0 degree &#8594 scan "A_t3" ,</li>
</ol>
and load protocol B of the steps:
<ol>
<li>initial state: &#949 = 0.0; &#966 = 0.0 degree &#8594 scan "B_t0"</li>
<li>(i) compression &#949 = -0.2; (ii) twisting &#966 = 20.0 degree &#8594 scan "B_t1"</li>
<li>(i) tension &#949 = 0.05; (ii) twisting &#966 = 0.0 degree &#8594 scan "B_t2"</li>
<li>end state: &#949 = 0.0; &#966 = 0.0 degree &#8594 scan "B_t3" .</li>
</ol>
Here, &#949 = u/l<sub>0</sub> is the axial strain given by the applied uniaxial displacement u in axial direction and the initial sample length l<sub>0</sub> = 46.5 mm. &#966 denotes the twisting angle w.r.t the axial direction. Both protocols were performed displacement/twisting angle controlled with the rates |d&#949/dt| = 0.01 /min and |d&#966/dt| = 1.0 deg/min for all changes, cf. file "protocols_A_and_B_visualization.pdf". The protocols differ only in the order in which the two boundary conditions are applied in steps 2 and 3 to investigate the sequence depending non-linear material behavior of superimposed loads.<br><br>

The files "utm_data_protocol_A.csv" and "utm_data_protocol_B.csv" contain the measured displacement, twisting angle, axial force, and torque from the Universal Testing Machine (UTM) over time for load protocols A and B, respectively. Scans were performed at t0, t1, t2, and t3 after 20 min previous relaxation time. A pause of about 12 hours was taken between the two loading protocols to allow the sample to relax. The image data sets are labeled according to the loading protocol (A, B) and the time step the micro-XRCT scan was performed (t0, t1, t2, t3), followed by a specification of the image data set ("projections", "reconstructed", "binarized"). Besides the projection and 3D reconstructed images, binarized images (foam skeleton and pore space) are provided.