Dynamic compression behaviour and microstructure of ZK60 alloy under different strain rates

2021 ◽  
pp. 1-13
Author(s):  
Zhi Wang ◽  
Shouben Huang ◽  
Feng Wang ◽  
Le Zhou ◽  
Di Tie ◽  
...  
Keyword(s):  
Dynamic Compression ◽  
Strain Rates ◽  
Compression Behaviour ◽  
Zk60 Alloy

Effect of aging-treatment on dynamic compression behaviour and microstructure of ZK60 alloy

2021 ◽  
Vol 37 (13) ◽  
pp. 1117-1128
Author(s):  
Zhi Wang ◽  
Shouben Huang ◽  
Feng Wang ◽  
Le Zhou ◽  
Di Tie ◽  
...  
Keyword(s):  
Dynamic Compression ◽  
Aging Treatment ◽  
Compression Behaviour ◽  
Zk60 Alloy

Experimental study of the out-of-plane dynamic behaviour of adhesively bonded composite joints using split Hopkinson pressure bars

2018 ◽  
Vol 52 (21) ◽  
pp. 2875-2885 ◽  
Author(s):  
S Sassi ◽  
M Tarfaoui ◽  
H Benyahia
Keyword(s):  
Strain Rate ◽  
Dynamic Behaviour ◽  
Dynamic Compression ◽  
Strain Rates ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Out Of Plane ◽  
Bonded Composite ◽  
Strong Material

The effect of the strain rate on the mechanical behavior and the damage of adhesively bonded joints is one of the most important factors to consider in designing them. Vast research has been carried out on the dynamic behaviour of adhesives at different strain rates; however, the investigation about the dynamic behaviour of the adhesively bonded joints is limited. In this paper, the main objective is to study and assess the effect of the strain rate on the out-of-plane mechanical behaviour of adhesively bonded joints under dynamic compression using Hopkinson bars. These joints are studied using glass/vinylester composite materials which are commonly used in naval applications. The experimantal results have shown a strong material sensitivity to strain rates. Moreover, damage investigations have revealed that the failure mainly occurred in the adhesive/adherent interface because of the brittle nature of the polymeric adhesive. Results have shown good agreement with the dependency of the dynamic parameters on strain rates.

Comparative studies of the constitutive models for tungsten heavy alloy (95W-3.5Ni-1.5Fe) at high strain rates

2021 ◽  
pp. 095440622110451
Author(s):  
Xiuwen Lai ◽  
Zhanjiang Wang ◽  
Na Qin
Keyword(s):  
Threshold Stress ◽  
Dynamic Compression ◽  
Constitutive Models ◽  
Heavy Alloy ◽  
Tungsten Heavy Alloy ◽  
Strain Rates ◽  
Stress Model ◽  
Static Compression ◽  
Mechanical Threshold ◽  
Wide Range

The plastic behaviors’ description of a tungsten heavy alloy (95W-3.5Ni-1.5Fe) at temperatures of 298–773 K and strain rates of 0.001–11,000 s−1 is systematically studied based on four constitutive models, that is, Zerilli-Armstrong model, modified Zerilli-Armstrong model, Mechanical Threshold Stress model, and modified Mechanical Threshold Stress model. The quasi-static compression experiments using an electronic universal testing machine and the dynamic compression experiments using a split Hopkinson pressure bar apparatus are employed to obtain the true stress–strain curves at a total of three temperatures (298 K, 573 K, and 773 K) and a wide range of strain rates (0.001–11,000 s−1). The parameters of the four constitutive models are obtained by the above fundamental experimental data and Grey Wolf Optimizer. The correlation coefficient and average absolute relative error are used to evaluate the predicted performance of these models. Modified Mechanical Threshold Stress model is found to have the highest predicted performance in describing the flow stress of the 95W-3.5Ni-1.5Fe alloy. Eventually, two compression experiments whose loading conditions are not in the fundamental experiments are conducted to validate the four models.

Microstructural and Dynamic Mechanical Characterization of Biodegradable Magnesium-Calcium Alloy for Orthopedic Implants

2014 ◽  
Author(s):  
V. S. Brooks ◽  
Y. B. Guo
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Orthopedic Implants ◽  
Strain Rates ◽  
High Strain Rates ◽  
Static Compression ◽  
Metallic Biomaterial

Magnesium-Calcium (Mg-Ca) alloy is an emerging metallic biomaterial for manufacturing biodegradable orthopedic implants. However, very few studies have been conducted on mechanical properties of the bi-phase Mg-Ca alloy, especially at the high strain rates often encountered in manufacturing processes. The mechanical properties are critical to design and manufacturing of Mg-Ca implants. The objective of this study is to study the microstructural and mechanical properties of Mg-Ca0.8 (wt %) alloy. Both elastic and plastic behaviors of the Mg-Ca0.8 alloy were characterized at different strains and strain rates in quasi-static tension and compression testing as well as dynamic split-Hopkinson pressure bar (SHPB) testing. It has been shown that Young’s modulus of Mg-Ca0.8 alloy in quasi-static compression is much higher than those at high strain rates. Yield strength and ultimate strength of the material are very sensitive to strain rates and increase with strain rate in compression. Strain softening also occurs at large strains in dynamic compression. Furthermore, quasi-static mechanical behavior of the material in tension is very different from that in compression. The stress-strain data was repeatable with reasonable accuracy in both deformation modes. In addition, a set of material constants for the internal state variable plasticity model has been obtained to model the dynamical mechanical behavior of the novel metallic biomaterial.

Shear band characteristics in high strain rate naval applications

2019 ◽  
Author(s):  
Michael J. P. Conway ◽  
James D. Hogan
Keyword(s):  
High Speed ◽  
Dynamic Compression ◽  
Shear Banding ◽  
Shear Bands ◽  
Critical Time ◽  
Strain Rates ◽  
Static Case ◽  
Dynamic Experiments ◽  
Naval Steels ◽  
Strain Responses

Abstract This paper explores the dynamic behavior of HSLA 65 naval steels, specifically focusing on the initiation and growth of shear bands in quasi-static and dynamic compression experiments and how these bands affect stress-strain responses. The results indicate that the yield strength for this HSLA 65 increases from 541 ± 8 MPa for quasi-static (10-3 s-1) to 1081 ± 48 MPa for dynamic rates 1853 ± 31 s-1, and the hardening exponent increases from 0.376 ± 0.028 for quasi-static to 0.396 ± 0.006 for dynamic rates. Yield behavior was found to be associated with the onset of shear banding for both strain-rates, confirmed through visualization of the specimen surface using high-speed and ultra-high-speed cameras. For the quasi-static case, shear banding and yielding was observed to occur at 2.5% strain, and were observed to grow at speeds of upwards of 38 mm/s. For the dynamic experiments, the shear banding begins at approximately 1.18 ± 0.06% strain and these can grow upwards of 2122 ± 213 m/s during post-yield softening. Altogether, these measurements are some of the first of their kind in the open literature, and provide guidance on the critical time and length scales in shear banding. This information can be used in the future to design more failure-resistant steels, which has broader applications in construction, defense, and natural resource industries.

Validation of the Tabulated Johnson-Cook Model for a Dynamic Compression Simulation

2015 ◽  
Vol 782 ◽  
pp. 245-251
Author(s):  
Guo Ju Li ◽  
Qun Bo Fan ◽  
Rui Hua Gao ◽  
Jin Tao Liu ◽  
Cheng Miao
Keyword(s):  
Effective Stress ◽  
Dynamic Compression ◽  
Effective Strain ◽  
Element Model ◽  
Strain Rates ◽  
Fitting Procedures ◽  
Data Points ◽  
Simulation Results ◽  
The Stability ◽  
Cook Model

MAT224 is a tabulated version of the Johnson-Cook model in LS-DYNA. Compared with the original Johnson-Cook material, MAT224 was developed to simulate the dynamic response of a material by just defining the effective stress as a function of effective plastic strain at different strain rates and temperatures, thus avoiding the tedious parameter fitting procedures in the traditional Johnson-Cook model. However, the stability and precision of solution is strongly dependent on the effective stress versus effective strain curves in MAT224, and unreasonable curve data will lead to warnings or errors in the process of solution. In the current study, a two-dimensional axisymmetric finite element model for the Ti-6Al-4V titanium alloy under dynamic compression was built, and MAT224 was employed. By investigating the effects of the curve numbers, strain ranges, data points, as well as changing tendencies, on the simulation results, the stability and the reliability for MAT224 are systematically studied.

Strain-Rate Dependence of Compressive Yield Strength of Titanium Grade 4 with Coarse-Grained and Ultrafine-Grained Structures: Experimental Results and Theoretical Calculation

2018 ◽  
Vol 1145 ◽  
pp. 100-105
Author(s):  
Ivan V. Smirnov ◽  
Alexander Y. Konstantinov
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
Yield Stress ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Pure Titanium ◽  
Coarse Grained ◽  
Strain Rates ◽  
Ultrafine Grained ◽  
Titanium Grade

The nanocrystalline (NC) and ultrafine-grained (UFG) structures of metallic materials can lead to their extraordinary high strength. However, most of the papers on this topic consider deformation parameters of NC and UFG materials only for the case of quasi-static tensile tests. Characteristics of dynamic strength and fracture of such materials remain unexplored. This paper presents a study of the mechanical behavior of pure titanium Grade 4 with a coarse-grained (CG) and UFG structure under uniaxial compression with different strain rates. The UFG structure was provided using the method of equal-channel angular pressing. The dynamic compression was carried out on a setup with the Split-Hopkinson pressure bar. It is found that in the observed range of strain rates 10–3-3×103 s–1, the yield stress of the CG titanium increases by 20%, and does not exceed the yield stress of the UFG titanium. However, the yield stress of the UFG titanium remains close to a quasi-static value. It is shown that these strain-rate dependencies of the yield strength can be predicted by the incubation time approach. The calculated curves show that at strain rates above 104 s–1 the yield stress of the CG titanium becomes higher than the yield strength of the UFG titanium.

scholarly journals The Dynamic Compressive Response of an Open-Cell Foam Impregnated With a Non-Newtonian Fluid

2009 ◽  
Vol 76 (6) ◽  
Author(s):  
M. A. Dawson ◽  
G. H. McKinley ◽  
L. J. Gibson
Keyword(s):  
Newtonian Fluid ◽  
Colloidal Silica ◽  
Dynamic Compression ◽  
Shear Thickening ◽  
Local Strain ◽  
Strain Rates ◽  
Parallel Plates ◽  
Compressive Response ◽  
Instantaneous Strain ◽  
Open Cell Foam

The response of a reticulated, elastomeric foam filled with colloidal silica under dynamic compression is studied. Under compression beyond local strain rates on the order of 1 s−1, the non-Newtonian, colloidal silica-based fluid undergoes dramatic shear thickening and then proceeds to shear thinning. In this regime, the viscosity of the fluid is large enough that the contribution of the foam and the fluid-structure interaction to the stress response of the fluid-filled foam can be neglected. An analytically tractable lubrication model for the stress-strain response of a non-Newtonian fluid-filled, reticulated, elastomeric foam under dynamic compression between two parallel plates at varying instantaneous strain rates is developed. The resulting lubrication model is applicable when the dimension of the foam in the direction of fluid flow (radial) is much greater than that in the direction of loading (axial). The model is found to describe experimental data well for a range of radius to height ratios (∼1–4) and instantaneous strain rates of the foam (1 s−1 to 4×102 s−1). The applicability of this model is discussed and the range of instantaneous strain rates of the foam over which it is valid is presented. Furthermore, the utility of this model is discussed with respect to the design and development of energy absorption and blast wave protection equipment.

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