复合材料梁弹性参数不确定性量化及试验验证

Uncertainty quantification on elastic parameters of composite beams and its experimental verification

为定量描述复合材料宏观力学性能的离散性,提出了仅有少量试验数据样本工况下,非均匀复合材料梁弹性模量的不确定性量化方法.基于梁不确定性弹性模量的谱分解模型,利用贝叶斯理论和蒙特卡罗模拟实现不确定性量化.对同一批次的复合材料梁开展试验研究,利用模态试验数据识别获得的梁弹性模量样本建立不确定性量化模型,并利用振动试验中实测动响应样本验证不确定性量化模型的正确性.该方法可以利用小样本试验数据,建立准确描述系统不确定性参数的量化模型,克服了传统概率模型需要大样本数据的缺陷,可以为复合材料结构的不确定性量化分析和可靠性评估提供参考.

An uncertainty quantification method was proposed for the elastic modulus of heterogeneous composite beams based on limited experimental data samples,to quantitatively describe the dispersity of the macroscopic mechanical properties of composites.With the spectral decomposition model of the uncertain elastic modulus of beams,the uncertainty quantification was achieved by the Bayesian theory and the Monte Carlo simulation.Experimental tests were conducted on the composite beams from the same batch,the uncertainty quantification model was constructed by the samples of the elastic modulus of beams identified from the modal test data,and the measured dynamic response samples from vibration tests were adopted to verify the correctness of the quantification model.The method can construct an accurate quantification model for uncertain system parameters with a small sample of experimental data.It overcomes the drawback of traditional probabilistic models which require large sample data.The proposed method provides references for the uncertainty quantification analysis and reliability evaluation of composite structures.