Welding is one of the most popular methods of connection that used across variety of industries to join together materials. Nondestructive testing methods are commonly used to verify that welds are free of defects. Some limitations to common NDT techniques have restricted their use. The new damage detection techniques are in need. This paper presents a study on the new inspection method. The advantage of this method is it's cost and time effectiveness. This study was conducted to investigate the ability of Inner product vector (IPV) method to detect Lack of Root Penetration (LOP) and Lack of side-wall fusion (LOSWF) on 304 stainless steel beam. The IPV method was proposed as a damage detection algorithm which uses cross correlation functions between vibration responses under white noise excitation. The experimental method was the only method of previous research on the IPV method. This will be achieved by the use of finite element modeling combined with a modal dynamic analysis based vibration technique and MATLAB software was used to numerically implement the computational procedure. In this study, an ideal welding is intended, and the effect of the heat-affected zone (HAZ) on the results is ignored. In order to verify the validity of the IPV method simulation, we refereed to the results of previous experimental research. The results obtained from modeling are compared with experimental results that showed good agreement.