Hello everybody. I've measured the Young Modulus of PDMS samples both in compression and in tension. From compressive tests I get a Modulus twice as big as the one I get from tensile tests. Is it normal to get two different values for Young Modulus using tensile or compressive tests? Do you think this behaviour is due to differences in molecular interactions? (eg: you need more energy to bring molecules together than to separate them (!?)) Thanks!