目前应变类损伤指标大多数只能利用损伤前后的模态参数进行损伤定位,但要得到损伤前的模态数据非常困难,难以在土木工程中推广应用。为此提出了无健康标准下基于损伤应变模态差分原理的直接定位损伤指标法ISMSD(Strain Mode Shape D iff...目前应变类损伤指标大多数只能利用损伤前后的模态参数进行损伤定位,但要得到损伤前的模态数据非常困难,难以在土木工程中推广应用。为此提出了无健康标准下基于损伤应变模态差分原理的直接定位损伤指标法ISMSD(Strain Mode Shape D ifference),只需利用损伤后应变模态数据即能定位损伤。推导了损伤应变模态等间距和不等间距差分格式。在综合考虑相邻两有效极值点间有效距离比、有效极值之差绝对值、有效极值绝对最大值的基础上,建立了直接定位损伤指标数学模型。根据理论推导和数值仿真统计分析,提出损伤位置判定准则:若某点的每阶指标值均最大,则该点有损伤;若某点的某阶或多阶指标值越大,则该点损伤可能性越大;对于某阶节点损伤,则可通过其余阶的指标值定位损伤。该指标能正确地判定损伤位置,尤其是损伤量较小情况。展开更多
The benchmark of a simply supported beam with damage and bending fuzzy stiffness consideration is established to be utilized for damage detection. The explicit expression describing the Rotational Angle Influence Line...The benchmark of a simply supported beam with damage and bending fuzzy stiffness consideration is established to be utilized for damage detection. The explicit expression describing the Rotational Angle Influence Lines(RAIL) of the arbitrary section in the benchmark is presented as the nonlinear relation between the moving load and the RAIL appeared, when the moving load is located on the damage area. The damage detection method is derived based on the Difference of the RAIL Curvature(DRAIL-C) prior to and following arbitrarily section damage in a simply supported beam with bending fuzzy stiffness consideration. The results demonstrate that the damage position can be located by the DRAIL-C graph and the damage extent can be calculated by the DRAIL-C curve peak. The simply supported box girder as a one-dimensional model and the simply supported truss bridge as a three-dimensional model with the bending fuzzy stiffness are simulated for the validity of the proposed method to be verified. The measuring point position and noise intensity effects are discussed in the simply supported box girder example. This paper provides a new consideration and technique for the damage detection of a simply supported bridge with bending fuzzy stiffness consideration.展开更多
文摘目前应变类损伤指标大多数只能利用损伤前后的模态参数进行损伤定位,但要得到损伤前的模态数据非常困难,难以在土木工程中推广应用。为此提出了无健康标准下基于损伤应变模态差分原理的直接定位损伤指标法ISMSD(Strain Mode Shape D ifference),只需利用损伤后应变模态数据即能定位损伤。推导了损伤应变模态等间距和不等间距差分格式。在综合考虑相邻两有效极值点间有效距离比、有效极值之差绝对值、有效极值绝对最大值的基础上,建立了直接定位损伤指标数学模型。根据理论推导和数值仿真统计分析,提出损伤位置判定准则:若某点的每阶指标值均最大,则该点有损伤;若某点的某阶或多阶指标值越大,则该点损伤可能性越大;对于某阶节点损伤,则可通过其余阶的指标值定位损伤。该指标能正确地判定损伤位置,尤其是损伤量较小情况。
基金the National Natural Science Foundation of China(Nos.51608245 and 51568041)the Natural Science Foundation of Gansu Province(No.148RJZA026)
文摘The benchmark of a simply supported beam with damage and bending fuzzy stiffness consideration is established to be utilized for damage detection. The explicit expression describing the Rotational Angle Influence Lines(RAIL) of the arbitrary section in the benchmark is presented as the nonlinear relation between the moving load and the RAIL appeared, when the moving load is located on the damage area. The damage detection method is derived based on the Difference of the RAIL Curvature(DRAIL-C) prior to and following arbitrarily section damage in a simply supported beam with bending fuzzy stiffness consideration. The results demonstrate that the damage position can be located by the DRAIL-C graph and the damage extent can be calculated by the DRAIL-C curve peak. The simply supported box girder as a one-dimensional model and the simply supported truss bridge as a three-dimensional model with the bending fuzzy stiffness are simulated for the validity of the proposed method to be verified. The measuring point position and noise intensity effects are discussed in the simply supported box girder example. This paper provides a new consideration and technique for the damage detection of a simply supported bridge with bending fuzzy stiffness consideration.
