An isogeometric simulation method for the temperature field of concrete dams based on dynamic evolution of birth-death elements

High-precision numerical simulation of temperature fields is crucial for the design and operation of concrete dams under severe conditions. However， in finite element analysis （FEA）， the discretized mesh model often deviates from the true geometric model， especially for structures with complex boundaries， where polygonal meshes approximate smooth geometries imperfectly. Currently， there is a lack of effective methods to quantify such model errors， making it difficult to guarantee the accuracy of numerical results based on error-affected models. To investigate how model errors influence the accuracy of temperature field calculations， a new metric—Discrete Geometry Fidelity Error （DGFE）—was proposed to quantitatively characterize the discrepancy between the geometric model and the mesh model. By comparing the DGFE of isogeometric analysis （IGA） and FEA， it was demonstrated that IGA can achieve higher geometric accuracy and numerical precision. For high-fidelity simulation of temperature fields in concrete dams， a heat conduction analysis method based on IGA was developed and applied to typical structures such as penstocks behind dams and cooling water pipes. The results show that this method offers both high solution accuracy and computational efficiency. Considering the layered construction process of concrete dams， the birth-death element technique was integrated with IGA to simulate the dynamic evolution of the temperature field during actual dam construction. Temperature analysis at two typical monitoring points revealed close agreement between simulation results and field measurements， with relative errors of only 3.8% and 2.8%， respectively. This confirms the effectiveness of IGA for dynamic thermal simulation in concrete dams， providing a geometrically precise and high-accuracy numerical approach for temperature field analysis of such complex structures.