| Summary: | 碩士 === 國防大學中正理工學院 === 軍事工程研究所 === 96 === For researches of reinforced concrete impacted by projectiles, numerical simulation have played an important role. The objectives of this study is to investigate the feasibility of parameter for numerical models of scaled impact tests
Based on Moxley's 0.295 and 0.5 scaled impact tests, numerical models were built by using LS-DYNA Software. For concrete material, three material models (MAT16、MAT72R3、MAT111) were used. Elastic-plastic behavior were considered for rebars. Effect of nonflecting boundary condition, time step, element size, and damage scaling were studied. Penalty factor, strain erosion criteria, ballistic limit, and concrete spalling were discussed.
The results showed that the MAT72R3 material model is the best model for concrete material with a principal strain erosion parameter of 0.48. The residual velocity of projectile after the perforation of scaled impact tests can be simulation by LS-DYNA Software with a maximum error of 10%. Compared with diameter of concrete spalling area from tests, the numerical model has a maximum error of 10% also.
By using MAT72R3 reinforced concrete material model and element erosion condition as 0.48, after gaining an effective numerical data, the error of residual velocity is 12.41％ for full scaled simulation of impact test.
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