scholarly journals Simulation of the Dynamic Behaviour of the ZTA Composites Obtained by Additive Technologies

2020 ◽  
Author(s):  
Vladimir Promakhov ◽  
Maksim Korobenkov ◽  
Nikita Schults ◽  
Ilia Zhukov ◽  
Viktor Klimenko ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Nonlinear Effects ◽  
Ceramic Composites ◽  
Additive Technologies ◽  
Mechanics Of Materials ◽  
Deformation And Fracture ◽  
Mesoscopic Level ◽  
Martensitic Phase Transformations ◽  
Strengthening Particles ◽  
Zro2 System

This paper presents a physical and mathematical model that has been developed in the framework of the approach used in the computational mechanics of materials. The model is designed to enable the study of the patterns of deformation and fracture of ceramic composites with a transformation-hardened matrix that are obtained by additive technologies at the mesoscopic and macroscopic levels under intense dynamic loading. The influence of the loading rate on the formation of the fracture and energy dissipation fronts for composite materials, based on the Al2O3 20%ZrO2 system, is shown. Nonlinear effects under intense dynamic loading in the considered composites are associated with the processes of self-organization of structural fragments at the mesoscopic level, as well as the occurrence of martensitic phase transformations in matrix volumes adjacent to the strengthening particles.

MODELING THE ACCUMULATION OF DAMAGES AND THE FAILURE OF CERAMIC COMPOSITES Al2O3-ZrO2, OBTAINED BY ADDITIVE TECHNOLOGIES, UNDER HIGH-SPEED LOADING

2021 ◽  
pp. 140-157
Author(s):  
V.V. Promakhov ◽  
◽  
M.V. Korobenkov ◽  
N.A. Schultz ◽  
A.S. Zhukov ◽  
...  
Keyword(s):  
Crack Resistance ◽  
High Speed ◽  
High Strength ◽  
Nonlinear Effects ◽  
Ceramic Composites ◽  
Additive Technologies ◽  
The Matrix ◽  
Mesoscopic Level ◽  
Martensitic Phase Transformations ◽  
Strengthening Particles

Functional ceramic composite materials are widely used in industry due to their high strength, hardness, high operating temperature, and chemical inertness. Among the most famous types of functional ceramics are the ceramic composites based on the Al2O3-20% ZrO2 system. In this work, the effect of the loading rate on the crack resistance is studied as well as the effect of the crack resistance of ceramic composites Al2O3-20% t-ZrO2 with a mass content of submicron tZrO2 particles on the high-speed compression of model specimens in shock waves and on the high-speed tension in the region of interaction of unloading waves. It is established that nonlinear effects of the mechanical behavior of ceramic composites ZrO2-Al2O3 with a transformationhardened matrix obtained by additive technologies are manifested at shock loading amplitudes close to or exceeding the Hugoniot elastic limit. Nonlinear effects under intense dynamic impacts on the considered composites are associated with the processes of self-organization of deformation regimes at a mesoscopic level, as well as with the occurrence of martensitic phase transformations in the matrix volumes, which are adjacent to strengthening particles. The modeling approach presented in this work can be used to determine the dynamic characteristics of ceramic composites up to shock loads of 1000 m/s.

scholarly journals Stress-Induced Martensitic Phase Transformations in NiTi Shape Memory Alloys During Dynamic Loading

2000 ◽  
Author(s):  
David A. Miller ◽  
W. Richards Thissell ◽  
George T. Gray ◽  
Duncan A. S. Macdougall
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Dynamic Loading ◽  
Void Growth ◽  
Split Hopkinson Pressure Bar ◽  
Large Strain ◽  
Martensitic Phase ◽  
Hopkinson Pressure Bar ◽  
Martensitic Phase Transformations ◽  
Niti Shape Memory Alloys

Abstract This research explores the near-adiabatic, high strain rate stress-induced martensitic phase transformation in NiTi shape memory alloys using both a compressive and tensile Split Hopkinson Pressure Bar (SHPB). The results of the dynamic loading tests are presented with emphasis on the loading rate, stress-strain response, specimen temperature and post-test microstructural evaluation. In addition to the large strain rates, tensile specimens of various geometries are tested to large strain levels such that void growth and failure mechanisms are identified. The dynamically loaded specimens failed in a mixed mode, ductile void growth followed by transgranular failure. The void growth in incipient failure specimens showed ductile void growth throughout the specimen cross-section.

Nonlinear effects in dynamic loading of a material with defect zones

1998 ◽  
Vol 24 (2) ◽  
pp. 99-101 ◽  
Author(s):  
S. G. Psakh’e ◽  
K. P. Zol’nikov ◽  
D. Yu. Saraev
Keyword(s):  
Dynamic Loading ◽  
Nonlinear Effects

scholarly journals Simplified strategies based on damage mechanics for concrete under dynamic loading

2017 ◽  
Vol 375 (2085) ◽  
pp. 20160170 ◽  
Author(s):  
Jacky Mazars ◽  
Stéphane Grange
Keyword(s):  
Dynamic Loading ◽  
Damage Mechanics ◽  
Experimental Testing ◽  
Damage Model ◽  
Nonlinear Effects ◽  
Strain Rates ◽  
Efficient Tool ◽  
Strain Rate Effects ◽  
Beam Elements ◽  
Rate Effects

Based on previous work, the µ damage model has been designed to figure out the various damage effects in concrete correlated with monotonic and cyclic loading, including unilateral effects. Assumptions are formulated to simplify constitutive relationships while still allowing for a correct description of the main nonlinear effects. In this context, the paper presents an enhanced simplified finite-element description including a damage description, based on the use of multifibre beam elements and including strain rate effects. Applications show that such a strategy leads to an efficient tool to simulate dynamic loading at low, medium and high velocities. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.

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