The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers

The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers are scrutinized using molecular dynamics simulations. A wide range chain length of alkane is tested under tension and shear with various temperatures. We find that the broken rate (the broken bond number to all polymer chain number ratios) under tension and shear increases with increasing chain length and temperature. For a given chain length and temperature, the broken rates under shear are always higher than those under tension at a same large strain. For a given chain length, the tensile and shear stresses decrease with increasing temperature. We propose three typical fracture mechanisms to effectively elucidate the ductile fracture response based on the predominance of chain scission process.