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...

The most common type of modal testing system today uses an FFT analyzer to measure a set of Frequency Response Functions (FRFs) from a structure, and then uses a parameter estimation (curve fitting) method to determine the structure’s modal properties from the FRF measurements. The curve fitting method typically “fits” an analytical model to the FRF data, (or its equivalent Impulse Response dat...

To estimate the modal parameters of Excavator Cab by conducting Multiple Input Multiple Output (MIMO) Modal Analysis test. MIMO testing is done to obtain Frequency response functions(FRF’s) either with two or more fixed inputs of forces and multiple outputs(called Input referencing) or with fixed multiple outputs and multiple inputs(called Output referencing). In the present testing, fixed inpu...

The modal testing has proven to be an effective and non-destructive test method for estimation of the dynamic stiffness and damping constant. The aim of the present paper is to investigate the modal response of stiffened Fiber Metal Laminated (FML) circular cylindrical shells using experimental and numerical techniques. For this purpose, three types of FML-stiffened shells are fabricated by a s...

With the fast development of data collection techniques, a huge amount of complex multi-modal data are generated, shared and stored on the Internet. The burden of extracting multi-modal features for test instances in data analysis becomes the main fact that hurts the efficiency of prediction. In this paper, in order to reduce the modal extraction cost in serialized classification system, we pro...

Abstract. We provide an empirical evaluation of one of the main test sets that is currently in use for testing modal satisfiability solvers, viz. the random modal QBF test set. We first discuss some of the background underlying the test set, and then evaluate the test set using criteria set forth by Horrocks, Patel-Schneider, and Sebastiani. We also present some guidelines for the use of the te...

Speed increase transmission gear box is the primary vibration and noise source of wind turbine, Operational modal method was adopted to collect impact data and response data of each point based on the gearbox test model. ANSYS finite element model is established to simulate the wind turbine gearbox. Then the modal frequencies of the two methods were compared to ensure the test model is correct....

Whenever experimentally derived (Test) modal vectors are compared to the analytically obtained (Analysis) modal vectors, for purpose of model verification or model updating, a transformation matrix must be utilized to expand/reduce the degrees offreedom, DOF, so that the spatial dimension of the two sets of modal vectors is the same. The measured set of DOF seldom match the analytical set of DO...

We present a semantic analysis of the Ramsey test, pointing out its deep underlying flaw: the tension between the “static” nature of AGM revision (which was originally tailored for revision of only purely ontic beliefs, and can be applied to higher-order beliefs only if given a “backwards-looking” interpretation) and the fact that, semantically speaking, any Ramsey conditional must be a modal o...

This paper presents a method for under-approximating behavioural models with the guarantee that the abstract paths can be instantiated as executions of the models. This allows a model-based testing approach to operate on an abstraction of an infinite or very large behavioural model. We characterize the abstract transitions as may, must+ or must-. This allows us to benefit from Thomas Ball’s res...