The output data from a structure is the building block for output-only modal analysis. The structure response in the output data, however, is usually contaminated with noise. Naturally, the success of output-only methods in determining the modal parameters of a structure depends on noise level. In this paper, the possibility and accuracy of identifying the modal parameters of a simply supported...

this paper uses a psopc model based non-destructive damage identification procedure using frequency and modal data. the objective function formulation for the minimization problem is based on the frequency changes. the method is demonstrated by using a cantilever beam, four-bay plane truss and two-bay two-story plane frame with different scenarios. in this study, the modal data are provided nume...

it is well known that damaged structural members may alter the behaviour of the structures considerably. careful observation of these changes has often been viewed as a means to identify and assess the location and severity of damages in structures. among the responses of a structure, natural frequencies and natural modes are both relatively easy to obtain and independent from external excitati...

the ambient vibration measurement is a kind of output data-only dynamic testing where the traffics and winds are used as agents responsible for natural or environmental excitation. therefore an experimental modal analysis procedure for ambient vibration testing needs to base itself on output-only data. the modal analysis involving output-only measurements present a challenge that requires the u...

this paper presents new sensitivity-based methods for detection of structural damage using incomplete noisy modal data. these methods are based on the first-order derivative of modal parameters. changes of natural frequency do not usually provide spatial information on the structural damage. they are also not sensitive to the local damage. in this paper, a new sensitivity function is proposed u...

According to the great importance of safety in aerospace industries, identification of dynamic parameters of related equipment by experimental tests in operating conditions has been in focus. Due to the existence of noise sources in these conditions the probability of fault occurrence may increases. This study investigates the effects of noise in the process of modal parameters identification b...

Modal verbs in English are challenging to learn by speakers of other languages. The purpose of thiswas to shed light on the use of gesture in learning English modal verbs by Persian-speaking children.To achieve this, 60 elementary Iranian learners, studying at some institutes in Karaj took part in thisstudy. The participants were randomly put into one experimental group and one control group. T...

marine industry requires continued development of new technologies in order to produce oil. an essential requirement in design is to be able to compare experimental data from prototype structures with predicted information from a corresponding analytical finite element model. in this study, structural model updating may be defined as the fit of an existing analytical model in the light of measu...

This paper uses a PSOPC model based non-destructive damage identification procedure using frequency and modal data. The objective function formulation for the minimization problem is based on the frequency changes. The method is demonstrated by using a cantilever beam, four-bay plane truss and two-bay two-story plane frame with different scenarios. In this study, the modal data are provided nume...

Abstract: Modal analysis is a powerful technique for understanding the behavior and performance of structures. Modal analysis can be conducted via artificial excitation, e.g. shaker or instrument hammer excitation. Input force and output responses are measured. That is normally referred to as experimental modal analysis (EMA). EMA consists of three steps: data acquisition, system identificatio...