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...

The following study deals with the updating the finite element model of structures using the operational modal analysis. The updating process uses an evolutionary optimization algorithm, namely bees algorithm which applies instinctive behavior of honeybees for finding food sources. To determine the uncertain updated parameters such as geometry and material properties of the structure, local and...

In this paper I will give a modal two-dimensional analysis of presupposition and modal subordination. I will think of presupposition as a non-veridical propositional attitude. This allows me to evaluate what is presupposed and what is asserted at different dimensions without getting into the binding problem. What is presupposed will be represented by an accessibility relation between possible w...

crack identification is a very important issue in mechanical systems, because it is a damage that if develops may cause catastrophic failure. in the first part of this research, modal analysis of a multi-cracked variable cross-section beam is done using finite element method. then, the obtained results are validated usingthe results of experimental modal analysis tests. in the next part, a nove...

this paper presents the effects of geometric tolerances on the rotating shafts natural frequencies. due to modeling the tolerances, a code is written in matlab 2013 software that produces deviated points. deviated points are controlled by different geometric tolerances, including cylindricity, total run-out and coaxiality tolerances. final surfaces and models passing through the points are crea...

determination of allowable free span length plays a crucial role in design of offshore pipelines. the seabed intervention cost and safety of an offshore pipelines project are largely influenced by pipelines free spanning during the project life time. different criteria are proposed by both the current designing guidelines and researchers there is however lack of comprehensive assessment of inde...