Damage localization using shape change in uniform load surface for civil large-span space structures

Civil large-span space structures have been widely built for public assembly venues. The failure of this type of structure may endanger the lives of many people. Considering that the member configuration of this type of structure may follow a regular pattern and damage in a local region may destroy the regular pattern, a damage detection approach based on the change in structural shape has been proposed by the present authors. In that approach, to obtain the change in structural shape due to damage, the displacements at joints between members are required to be measured. Since it is difficult to measure displacements on this type of structure in practice, in this study, the authors proposed to use the shape change of the uniform load surface for damage localization. Uniform load surface physically represents the deflection profile of the structure under the assumed uniformly distributed loading and can be calculated from the flexibility matrix constructed from the identified natural frequencies and mode shapes. This approach can locate damage to exact structural members. It will avoid costly and tedious work in measuring displacements. This approach has been numerically validated on single-layer space structures with two different member configurations.

Locate Damage Based on Change in Structural Shape Calculated From Uniform Load Surface

Reticulated shell structures have been widely built for public assembly venues, where many people get together during events. Therefore, it is important to conduct condition assessment for this type of structure to ensure the safety of the general public. Considering that the member configuration of this type of structure may follow a regular pattern and damage in a local region may destroy the regular pattern, a damage detection approach based on the change in structural shape is proposed in this study. The change in structural shape can be obtained from the displacement at each joint. Since it may be difficult to measure displacements on this type of structure, it is proposed to use the uniform load surface calculated from the constructed modal flexibility matrix to represent displacements at joints. Therefore, this approach requires the measurement of acceleration responses, instead of displacement measurement. For validating the feasibility of the proposed approach, numerical simulations are conducted on a single-layer dome structure with different levels of damage severity considered. The obtained results verify that the proposed approach is capable of locating damage to exact members.