Abstract: In this paper, thermal expansion properties of single and hybrid multi-directional composites from r.t. to 150℃ arc studied. The theoretical formulae for predicting coefficient of thermal expansion (CTE) value arc established. In the experiments, carbon/glass and carbon / Kcvlar arc accepted to be the hybrid form. The variation of CTE values of hybrid composites with structure parameters is analyzed. Besides, hybrid composites with zero CTE are studied and designed. And some typical ply forms of laminates with zero CTE are presented. The investigation shows that it is easier for hybrid multi-directional composites to meet the requirement of zero-expansion.

Key words: composites, hybrid, coefficient of thermal expansion, laminate