Overhead crane bridge structure design optimization based on safety assessment

In order to achieve safe and economical design results for crane bridge structures, an optimization method with safety assessment constraints is proposed. In this approach, the limit state method is used to test the structure design. Safety assessment is conducted based on the fuzzy analytic network process, allowing the safety score of designs to be quantified. Aiming to minimize the self-weight of the bridge, the dimensions of critical sections are regarded as design variables and constraints related to the process size, strength, stiffness, stability, and safety score are imposed, utilizing the artificial hummingbird algorithm for the structure optimal design. After validating through an engineering example, the results demonstrated that under the settled safety constraints, the proposed optimization method successfully reduced the structural self-weight by 19.709%, while maintaining a safety score proximate to the original design. In comparison to optimization without safety assessment constraints, this method resulted in a 10.441% increase in weight, but its safety was significantly improved by 21.740%. This validates the effectiveness and practicality of incorporating safety assessment into structure optimization, thereby ensuring a balanced trade-off between safety and material economy in the design of crane bridge structures.