Dynamic behavior of a concrete building under mainshock-aftershock seismic sequence with a progressive damage and failure material model

2016 ◽  
pp. 695-699
Author(s):  
J Dulinska ◽  
I Murzyn
Keyword(s):  
Dynamic Behavior ◽  
Material Model ◽  
Progressive Damage ◽  
Seismic Sequence ◽  
Damage And Failure ◽  
Concrete Building

Experimental characterization of composites to support an orthotropic plasticity material model

2017 ◽  
Vol 52 (14) ◽  
pp. 1847-1872 ◽  
Author(s):  
Bilal Khaled ◽  
Loukham Shyamsunder ◽  
Canio Hoffarth ◽  
Subramaniam D Rajan ◽  
Robert K Goldberg ◽  
...  
Keyword(s):  
Material Model ◽  
Unidirectional Composite ◽  
Deformation Model ◽  
Test Results ◽  
Dynamic Impact ◽  
Test Procedures ◽  
Stress Strain ◽  
Damage And Failure ◽  
Orthotropic Behavior

Test procedures for characterizing the orthotropic behavior of a unidirectional composite at room temperature and quasi-static loading conditions are developed and discussed. The resulting data consisting of 12 stress–strain curves and associated material parameters are used in a newly developed material model—an orthotropic elasto-plastic constitutive model that is driven by tabulated stress–strain curves and other material properties that allow for the elastic and inelastic deformation model to be combined with damage and failure models. A unidirectional composite—T800/F3900, commonly used in the aerospace industry, is used to illustrate how the experimental procedures are developed and used. The generated data are then used to model a dynamic impact test. Results show that the developed framework implemented into a special version of LS-DYNA yields reasonably accurate predictions of the structural behavior.

Experimental and numerical analysis of progressive damage and failure behavior of carbon Woven-PPS

2020 ◽  
Vol 243 ◽  
pp. 112234
Author(s):  
Leila Jebri ◽  
Fethi Abbassi ◽  
Murat Demiral ◽  
Mohamed Soula ◽  
Furqan Ahmad
Keyword(s):  
Numerical Analysis ◽  
Failure Behavior ◽  
Progressive Damage ◽  
Damage And Failure

scholarly journals Numerical Study on the Critical Frequency Response of Jet Engine Rotors for Blade-Off Conditions against Bird Strike

2019 ◽  
Vol 9 (24) ◽  
pp. 5568 ◽  
Author(s):  
Saeed Badshah ◽  
Ahsan Naeem ◽  
Amer Farhan Rafique ◽  
Ihsan Ul Haq ◽  
Suheel Abdullah Malik
Keyword(s):  
Modal Analysis ◽  
Dynamic Behavior ◽  
Critical Frequency ◽  
Material Model ◽  
Operating Conditions ◽  
Mode Shapes ◽  
Bird Strike ◽  
Critical Mode ◽  
Jet Engine ◽  
Engine Rotor

Vibrations are usually induced in aero engines under their normal operating conditions. Therefore, it is necessary to predict the critical frequencies of the rotating components carefully. Blade deformation of a jet engine under its normal operating conditions due to fatigue or bird strike is a realistic possibility. This puts the deformed blade as one of the major safety concerns in commercially operating civil aviation. A bird strike introduces unbalanced forces and non-linearities into the engine rotor system. Such dynamic behavior is a primary cause of catastrophic failures. The introduction of unbalanced forces due to a deformed blade, as a result of a bird strike, can change the critical frequency behavior of engine rotor systems. Therefore, it is necessary to predict their critical frequencies and dynamic behavior carefully. The simplified approach of the one-dimensional and two-dimensional elements can be used to predict critical frequencies and critical mode shapes in many cases, but the use of three-dimensional elements is the best method to achieve the goals of a modal analysis. This research explores the effect of a bird strike on the critical frequencies of an engine rotor. The changes in critical mode shapes and critical frequencies as a result of a bird strike on an engine blade are studied in this research. Commercially available analysis software ANSYS version 18.2 is used in this study. In order to account for the material nonlinearities, a Johnson Cook material model is used for the fan blades and an isotropic–elastic–plastic–hydrodynamic material model is used for modeling the bird. The bird strike event is analyzed using Eularian and smoothed particle hydrodynamics (SPH) techniques. A difference of 0.1% is noted in the results of both techniques. In the modal analysis simulation of the engine rotor before and after the bird strike event, the critical failure modes remain same. However, a change in the critical frequencies of the modes is observed. An increase in the critical frequencies and excitation RPMs (revolution per minute) of each mode are observed. As the mode order is increased, the higher the rise in critical frequency and excitation RPMs. Also, a change in the whirl direction of the different modes is noted.

scholarly journals Study on modified Johnson-Cook constitutive material model to predict the dynamic behavior Mg-1Al-4Y alloy

2020 ◽  
Vol 7 (2) ◽  
pp. 026522
Author(s):  
Jinhui Wang ◽  
Xiaoguang Yuan ◽  
Peipeng Jin ◽  
Hongbin Ma ◽  
Bo Shi ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Material Model ◽  
Constitutive Material Model ◽  
Constitutive Material
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