基于交变应力的碳纤维杉木复合材蠕变性能研究

采用基于交变应力的抗弯试验方法对碳纤维杉木复合材在干、湿环境条件下的短期蠕变性能进行研究.结果表明：Burger模型可较精确地模拟复合材的短期弯曲蠕变性能;湿环境下复合材蠕变量显著大于干环境,温度及相对湿度是影响蠕变的重要因素;在应力变化周期为1h时,交变应力下蠕变量稍低于恒定应力水平,交变应力未加速蠕变的进程;在湿环境中高应力水平下复合材蠕变速率最大,较短时间便出现压溃破坏,在复合材设计应用时,应综合考虑环境状态及应力水平的影响,将应力水平极值控制在极限应力的40％以内.

Alternative Stress-Based Creep Properties of CFRP-Wood Composite Materials

The alternative stress based bending resistant experiment was applied to study the short term bending creep performance of carbon fibre reinforced polymer （CFRP） under both dry and wet environmental conditions. The results showed that the Burger Model could precisely simulate the short-term bending creep performance of the composite material. Under the wet condition, the creep change amount of the composite material was significantly larger that of under the dry condition. It was showed that both of the relative humidity and temperature were impor- tant factors to affect the creep change. When the stress change cycle was 1 h, the creep change under alternative stress was slightly lower than that of under the constant stress, indicating that the alternative stress did not accelerate the creep change process. The maximum creep change rate occurred under wet environmental condition with high stress level which led to the fracture of the composite material within short time. The environmental conditions and stress level should be integratedly considered while designing and applying the composite material. The stress level should be controlled to be within 40% of the maximum value.