Dynamic testing and numerical simulation of human-induced vibration of cantilevered floor with tuned mass dampers

Static and dynamic testing of specimens specially designed for studying the localization of plastic deformation in AMg6 and D16 alloys were performed on then electromechanical Testometric machine and split Hopkinson pressure bar using the StrainMaster system for noninvasive measurement of shape and deformation. Displacement and strain fields are plotted for special-shaped specimens of AMg6 and D16 alloys subjected to static deformation and dynamic loading. Comparison between the experimentally obtained strain fields and the results of numerical simulation made with account of the kinetics of microdefect accumulation in the examined material demonstrates good agreement to the accuracy of ~20%. The performed tests and their numerical simulation with consideration for the evolution of the defect material structure confirm the concept of the strain localization mechanism associated with the processes in the system of microdefects.

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GTN Damage Modelling of the AA6063 Using Image Processing

Brilliant Engineering ◽

10.36937/ben.2022.4400 ◽

2021 ◽

Vol 3 (1) ◽

pp. 1-4

Author(s):

Saurabh Rai

Keyword(s):

Numerical Simulation ◽

Image Processing ◽

Dynamic Testing ◽

Damage Model ◽

Dynamic Test ◽

Processing Technique ◽

Image Processing Technique ◽

Simulation And Optimization ◽

Damage Models ◽

Heat Treated

In this paper, an innovative way of calculating the Gurson–Tvergaard–Needleman parameter has been developed for AA 6063. AA 6063 is an aluminum alloy comprising the alloying ingredients magnesium and silicon. The Aluminum Association maintains the standard that governs its composition. It has strong mechanical properties and may be heat treated and welded. Image processing technique has been used to calculate the damage constant for the AA 6063. The image of the sample has been taken under a microscope of undeformed and fractured material. Then the images are analyzed using the Open CV tool in a python open-source environment. The initial and final void fraction of the sheet has been calculated. Damage models, particularly the Gurson–Tvergaard–Needleman (GTN) model, are widely used in numerical simulation of material deformations. Each damage model has some constants which must be identified for each material. The direct identification methods are costly and time-consuming. A combination of experimental, numerical simulation and optimization have been used to determine the constants in the current work. Numerical simulation of the dynamic test was performed utilizing the constants obtained from quasi-static experiments. The results showed a high precision in predicting the specimen's profile in the dynamic testing.

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Optimal Design and Practical Considerations of Tuned Mass Dampers for Structural Control

Design Optimization of Active and Passive Structural Control Systems ◽

10.4018/978-1-4666-2029-2.ch006 ◽

2013 ◽

pp. 126-149

Author(s):

Chi-Chang Lin ◽

Jer-Fu Wang

Keyword(s):

Numerical Simulation ◽

Structural Control ◽

Three Dimensional ◽

Design Procedure ◽

Experimental Tests ◽

Movement Direction ◽

Empirical Formulas ◽

Tuned Mass Dampers ◽

Structure Interaction ◽

Building Models

The design concept and procedure for tuned mass dampers (TMDs) have been extensively investigated through numerical simulation analyses and experimental tests. Sophisticated three-dimensional building models were developed to examine the optimum installation location in elevation and in plane, number and movement direction of the TMDs with the consideration of translation-torsion coupling and soil-structure interaction effects. Analytical and empirical formulas were also derived to determine the optimal parameters of TMD. It is well recognized that the performance of a TMD is sensitive to the slight deviation of frequency ratio between the TMD and the structure. Multiple tuned mass dampers (MTMDs) were proposed to reduce this detuning effect. It is also recognized that TMD’s performance relies on its large stroke which may not be allowed due to the limitation of space and vibration components. The authors presented a two-stage optimum design procedure for MTMDs with limitation of their strokes. New invention patents both in Taiwan and in USA have been granted for the MTMD device.

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