炭布叠层针刺预制体性能分析

通过X-Y向拉伸强度、Z向剥离强力、NOL环整体拉伸强度表征预制体性能,研究了炭布叠层针刺预制体的结构特点.结果表明:X-Y向拉伸强度反映了针刺对连续纤维的损伤程度,其随针刺密度升高而降低.网胎面密度对Z向预制体剥离强力的影响规律性不明显,3 K炭布针刺预制体剥离强力高于6K和12K炭布针刺预制体,斜纹炭布针刺预制体剥离强力高于缎纹炭布预制体.NOL整体拉伸环破坏有完全断裂、褶皱式不完全断裂、层间剥离三种模式;3 K缎纹炭布针刺预制体NOL环拉伸强度最低,只有3 MPa,呈现整体拉伸完全断裂破坏模式;12 K缎纹炭布针刺预制体呈现层间破坏模式;6 K缎纹炭布针刺预制体的破坏方式为褶皱式不完全断裂模式,整体力学性能较好.相同工艺预制体环向拉伸强度远大于X-Y向拉伸强度.

Performance analysis of a carbon cloth/felt layer needled perform

The structural characteristics of a carbon cloth/felt layer needled preform are investigated. X-Y direction tensile strength, Z direction peel-off stress, and the Naval Ordnance Laboratory (NOL) ring-integrated tensile strength were tested. The X-Y direction tensile strength decreased with the increase of needling density. The law of surface density of fiber felt affecting the Z direction stress is not obvious. Peel-off stress of a 3 K carbon cloth/felt needled preform is higher than that of 6 K and 12 K cloth/felt, and the peel-off stress of a diagonal carbon cloth/felt needled preform is better than that of a satin one. There are three different damage modes for the NOL-integrated tensile ring, namely complete rupture, incomplete rupture, and interlayer peel-off. For 3 K satin carbon cloth/felt needling preform, its NOL ting-integrated tensile strength is the lowest and only 3 MPa, and it shows complete rupture. For the 12K satin carbon cloth/felt needled preform, the damage mode is interlayer peel-off , and for the 6 K satin carbon cloth/felt needled preform, the damage mode is incomplete rupture, and its integrated mechanical performance is excellent. NOL ting-integrated tensile strength is much higher than X-Y tensile intensity for the preforms made by same process.