scholarly journals Effect of Heat Treatment Process and Composition on Deformation and Damage Behavior of WHA under Detonation Loading

2021 ◽  
Vol 2101 (1) ◽  
pp. 012067
Author(s):  
J J Tang ◽  
Z F Liang ◽  
X Y Hu

Abstract The excellent material properties of tungsten heavy alloy (WHA) make it widely used in the military field. When used as killing elements of weapons, its dynamic mechanical properties under detonation loading directly determine the damage effect of weapons, which makes the research on its mechanical behaviors under high pressure and high strain rate loads such as detonation loading of great significance. In this paper, several WHAs with different compositions and processes are selected, and the mechanical properties and deformation and damage behavior under static explosion test are analyzed by combining macro and micro study, so as to provide guidance for the subsequent optimization of the performance design of WHA.

Entropy ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1154
Author(s):  
Bingfeng Wang ◽  
Chu Wang ◽  
Bin Liu ◽  
Xiaoyong Zhang

The dynamic mechanical properties and microstructure of the (Al0.5CoCrFeNi)0.95Mo0.025C0.025 high entropy alloy (HEA) prepared by powder extrusion were investigated by a split Hopkinson pressure bar and electron probe microanalyzer and scanning electron microscope. The (Al0.5CoCrFeNi)0.95Mo0.025C0.025 HEA has a uniform face-centered cubic plus body-centered cubic solid solution structure and a fine grain-sized microstructure with a size of about 2 microns. The HEA possesses an excellent strain hardening rate and high strain rate sensitivity at a high strain rate. The Johnson–Cook plastic model was used to describe the dynamic flow behavior. Hat-shaped specimens with different nominal strain levels were used to investigate forced shear localization. After dynamic deformation, a thin and short shear band was generated in the designed shear zone and then the specimen quickly fractured along the shear band.


2019 ◽  
Vol 17 (06) ◽  
pp. 1950013 ◽  
Author(s):  
Liping Ying ◽  
Yijiang Peng ◽  
Hongming Yang

In this paper, the base force element method (BFEM) for dynamic damage problems is proposed. And the BFEM model was applied to investigate the dynamic mechanical behavior of recycled aggregate concrete (RAC). Any convex polygon recycled aggregate was simulated. A constitutive relationship of dynamic damage was given. The compression test under dynamic loadings on the recycled concrete specimen was simulated. The stress–strain softening curve, variation law of dynamic enhancement coefficient and the damage pattern were researched under different strain rates. The dynamic properties of recycled concrete materials at high strain rate are also studied. The effect of different aggregate distribution on the mechanical properties of concrete was studied. The results of dynamic calculation of recycled concrete materials by this method are compared with the experimental results. The numerical simulation results are in good agreement with the experimental results. The comparative analysis on the dynamic mechanical properties of RAC and natural aggregate concrete (NAC) was also studied. The results show that the BFEM can be used to analyze the dynamic mechanical properties of RAC and NAC under high strain rate, and can be used for large-scale engineering calculations.


Polymer ◽  
2005 ◽  
Vol 46 (10) ◽  
pp. 3528-3534 ◽  
Author(s):  
Xiangyang Hao ◽  
Guosheng Gai ◽  
Fangyun Lu ◽  
Xijin Zhao ◽  
Yihe Zhang ◽  
...  

Author(s):  
Xu Long ◽  
Minghui Mao ◽  
Changheng Lu ◽  
Ruiwen Li ◽  
Fengrui Jia

Great progress has been made in the dynamic mechanical properties of concrete which is usually assumed to be homogenous. In fact, concrete is a typical heterogeneous material, and the meso-scale structure with aggregates has a significant effect on its macroscopic mechanical properties of concrete. In this paper, concrete is regarded as a two-phase composite material, that is, a combination of aggregate inclusion and mortar matrix. To create the finite element (FE) models, the Monte Carlo method is used to place the aggregates as random inclusions into the mortar matrix of the cylindrical specimens. To validate the numerical simulations of such an inclusion-matrix model at high strain rates, the comparisons with experimental results using the split Hopkinson pressure bar are made and good agreement is achieved in terms of dynamic increasing factor. By performing more extensive FE predictions, the influences of aggregate size and content on the macroscopic dynamic properties (i.e., peak dynamic strength) of concrete materials subjected to high strain rates are further investigated based on the back-propagation (BP) artificial neural network method. It is found that the particle size of aggregate has little effect on the dynamic mechanical properties of concrete but the peak dynamic strength of concrete increases obviously with the content increase of aggregate. After detailed comparisons with FE simulations, machine learning predictions based on the BP algorithm show good applicability for predicting dynamic mechanical strength of concrete with different aggregate sizes and contents. Instead of FE analysis with complicated meso-scale aggregate pre-processing, time-consuming simulation and laborious post-processing, machine learning predictions reproduce the stress–strain curves of concrete materials under high strain rates and thus the constitutive behavior can be efficiently predicted.


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