I think this ASTM standard might help

ASTM D5024

Standard Test Method for Plastics: Dynamic Mechanical Properties: In Compression

Please check these articles which I think would be helpful

1.https://www.astm.org/Standards/F2150.htm

2. An Overview of Mechanical Tests for Polymeric Biomaterial Scaffolds Used in Tissue Engineering Oscar Robles-Vazquez1 , Ignacio Orozco-Avila2 , Juan C. Sánchez-Díaz1 and Elena Hernandez1,

3. Compression test on porous polymeric scaffolds A.Parrilli1,2, F.Salamanna1 , F.Veronesi1 , L.Ambrosio3 , A.Salerno4,5, M.Fini1

(http://bruker-microct.com/company/UM2009/abstract_020.pdf)

4. MECHANICAL TESTING METHODS OF CUBIC SUB-SIZED COMPRESSION SAMPLES FOR POLYMERIC TISSUE-ENGINEERED SCAFFOLDS T.P. Quinn (1), J.D. McColskey (1), N.R. Washburn (2), and C.N. McCowan (1) http://www.tulane.edu/~sbc2003/pdfdocs/1201.PDF

I believe the first question to ask here is what properties you are interested in and based on that you have to design your experiments.

For example, if you are simply interested in the compression stiffness then the flat punch nanoindentation or other systems would work. If you are interested in the complex modulus then the nanoindentation has to be performed with appropriate methods.

Hope it helps!