Database on Material Dynamic Strength
Creation of Database on Dynamic Strength Properties of Construction Materials
Tech Area / Field
- PHY-SSP/Solid State Physics/Physics
8 Project completed
Senior Project Manager
Rybakova T A
VNIIEF, Russia, N. Novgorod reg., Sarov
- Sandia National Laboratories, USA, NM, Albuquerque
Project summaryThe Project is aiming at creation of database using experimental results of construction materials behaviour tests performed mainly in VNIIEF (metals, alloys, polymeric and composite materials, compounds, etc) at different stressed states, loading rates and temperatures. Material dynamic characteristics are needed to construct state equations and to create computational models representing real material behaviour at different temperature/time effects. Experimental results are also needed to estimate reliability of high-stressed elements constituent of modern constructions experiencing dynamic loadings as well as to develop optimum dynamic technologic processes.
The first part will be dedicated to description of developed and implemented by the authors’ methods to study dynamic stress and strain material characteristics under one-axial and two-axial stressed state. Dynamic loading at high strain rates, as a rule, results in unstationary fields with inhomogeneous strain. Due to it, of special interest are quazistatic investigation methods, where the sample operating part is in uniformly stressed and strained state. One of the most effective presently used quazistatic methods to define material mechanic properties under one-axial dynamic tension and compression is Gopkinson's compound rod method (GCR). This method to test constructional materials at e = 10 ё 103s-1 strain rates has correct computational and experimental backgrounds. On the basis of the method VNIIEF have developed and implemented more than 20 years ago test facilities with explosive damping loading which can be performed both in laboratory and field conditions. Explosive loading device can create pulsed loadings of trapezoidal form and to vary loading amplitude within a wide range, which allows to test materials having their strength varying by tenfolds. Using compact thermostates makes it possible to perform dynamic testings both at decreased (-40°C) and increased (up to +300°C) temperatures. The main advantage of explosive loading is a possibility to synchronize pulsed mechanic loading with other pulsed outer effects such, as pulsed electric heating or h-g radiation.
Dynamic material testings at complicated stressed (two-axial) state are performed in VNIIEF under simultaneous/independent effect on tube-shaped samples in axial and radial directions. Smooth loading variation allows determining stress and strain material characteristics from pure one-axial to pure radial loading at different axial/radial loadings correlations. Two-axial dynamic tests were also made on semi-spherical samples at inner explosive loading. Strain and stress characteristics were defined at uniform two-axial loading.
Experimental data was collected and processed using measuring/computation complex with a cluster of applicated codes. The second Project part would reveal dynamic testings results for the wide range of construction materials.
Material behaviour study results at one-axial and two-axial loading would be summarized as the 'database. The main portion of the above results has been published in scientific journals, proceedings of international conferences and symposiums. Published as well are mathematics models of material behaviour under pulsed loading developed by VNIIEF associates.
Execution of this Project is associated with collection, analysis and summarizing of published by some other VNIIEF authors results of material dynamic properties studies.
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