This paper carries out dynamic tests of self-compacting prestressed concrete beams, 10 simply-supported and 5 free, then simulates modal analyses. It shows that, via comprehensive analyses of the first four natural frequencies and modes, the simple support can not achieve the ideal confinement effect for dynamic tests. Especially the tested high frequencies and modes are obviously different from corresponding theoretical values, instead the same as elastic-supported beams. The support plays the role of elastic one. The conclusions will provide meaningful references to further researches on pre...
