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The discretization error is not always calculated, even though it is essential for the studies of computational solid mechanics. However, it is well known that an error committed by the mesh used can be as large as the measured variable, which greatly invalidates the results obtained. The grid convergence index (GCI) method makes possible to determine on a solid basis, the order of convergence and the asymptotic solution. This method seems to be a suitable estimator despite further research is needed in the context of blast situations and finite element (FE) calculations. For this purpose, field trials were performed consisting in the detonation of a spherical hanging load of homemade explosive. The pressure generated by the shock wave was measured in different positions at two distances. With these data, a TNT equivalent has been obtained and used to calculate the shock propagation with the solvers LS-DYNA and ProsAir. This work aims to verify the GCI method by comparing its results with field data along with the simulations carried out. The comparison also seeks to validate the methodology used to obtain the TNT equivalent.This research shows that the GCI gives good results for both solvers despite the complexity of the physical problem. Besides, LS-DYNA displays better correlation with the experimental data than the ProsAir results, with an error of less than 10% in all values. RESUMENLa estimación del error de discretización no siempre se calcula, aunque es algo fundamental para el estudio de la mecánica computacional de los sólidos. Sin embargo, es bien sabido que el error cometido por la malla utilizada puede ser del mismo orden que la variable medida, lo que llega a invalidar los resultados obtenidos. El método del ındice de convergencia de la malla (GCI) permite determinar sobre una base sólida el orden de convergencia y la solución asintótica, por lo que parece ser un buen estimador, a pesar de que es necesario seguir investigando en el contexto de las situaciones de ondas de choque (explosivos) y de los cálculos de elementos finitos (FE). Para este fin, se realizaron pruebas de campo consistentes en la detonación de una carga esférica colgada de explosivo casero. La presión generada por la onda de choque se midió en diferentes posiciones a dos distancias. Con estos datos, se obtuvo un equivalente de TNT que se utilizó para calcular la propagación del choque con los programas LS-DYNA y ProsAir. Este trabajo pretende verificar el método GCI comparando sus resultados con los datos de campo junto con las simulaciones realizadas. También, la comparación busca validar la metodologıa empleada para la obtención del equivalente TNT.La investigación muestra que el GCI da buenos resultados para ambos programas a pesar de la complejidad del problema fısico. Además, el LS-DYNA produce una mejor correlación con los datos experimentales que los aportados por el ProsAir, con todos los valores por debajo del 10 % de error.Palabras clave: ındice de convergencia de malla (GCI), equivalente de TNT, LS-DYNA, ProsAir.How to ...

Numerical simulation of reinforced concrete (RC) slabs with the addition of an external reinforced polymer (FRP) have been developed and compared with full scale real tests. The size of the slabs was 4.4 x 1.46 m, with a span of 4 m, and a thickness of 15 cm. The slabs were built using concrete of class C25/30, and B500C reinforcing steel. Seven tests were conducted, one at a scaled distance of 0.83 m/kg 1/3 , three at a scaled distance of 0.42 m/kg 1/3 , and three at 0.21 m/kg 1/3 . For the biggest scaled distance, the slab had no extra reinforcement. In the other two cases one of the slabs had no extra reinforcement, while the other two tests were performed with carbon fibre reinforcement (CFRP) and E-glass fibre reinforcement (GFRP) located on the face opposite to the blast. Numerical simulation was performed with LS-DYNA software. The study elements (concrete, steel and reinforcement) have been simulated in a Lagrangian formulation with solid elements, beam elements and shells, respectively. Three concrete models have been used and compared: CSCM, MAT72-R3 and RHT. As for the explosive, the CONWEP-based Load Blast Enhanced (LBE) card was used. Reinforcement with CFRP resulted in a generally reduced damage area on both surfaces. All models show a good correlation with the test results and a non-destructive damage estimation technique when comparing them in terms of damage area.