||The local flexibility method (LFM),which can determine local stiffness variations of beam structures using measured modal parameters, is founded on virtual forces that cause nonzero stresses within a local part of the structure and zero stresses in the other parts of a structure. In this study, the pseudo local flexibility method (PLFM) which breaks the “zero stresses rule” for better damage detection results is proposed. The proposed approach was verified by numerical studies and experimental study of a continuous beam and fix-end beam. The results show that much fewer modes are required for the PLFM to estimate the damage locations and extents with acceptable accuracy. In this study another modification of LFM was also proposed. The “rotatory displacement” mode shapes were extracted from macro-strain vibration signals. These rotatory displacement mode shpaes were employed to detect damage of a beam structure utilizing the local flexibility method. The proposed approach was verified by numerical studies and experimental studies of a simply supported beam. Using the same number of modes, the numerical studies results using “rotatory displacement” mode shapes was better comparing to the one using “lateral displacement” mode shapes. The experimental results show that using “rotatory displacement” mode shape has only similar damage detection ability comparing to using “lateral displacement” mode shape, probably due to that the noise level of measurement during experiment is very small and the signal to noise ratio of lateral vibration signals is very large comparing to the macro-strain ones. In addition, using these two proposed modifications, the sensitivity of damage is improved due to small range of the concentration stress introduced by the designated virtual forces. As a result, damage close to supports should be easiser to be detected.