scholarly journals Temperature-dependent yield asymmetry between tension and compression in metallic glasses

2012 ◽  
Vol 61 (3) ◽  
pp. 036201
Author(s):  
Chen Yan ◽  
Jiang Min-Qiang ◽  
Dai Lan-Hong
Keyword(s):  
Metallic Glasses ◽  
Temperature Dependent ◽  
Tension And Compression

scholarly journals A General Temperature-Dependent Stress–Strain Constitutive Model for Polymer-Bonded Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1393
Author(s):  
Xiaochang Duan ◽  
Hongwei Yuan ◽  
Wei Tang ◽  
Jingjing He ◽  
Xuefei Guan
Keyword(s):  
Composite Materials ◽  
Constitutive Model ◽  
Model Parameters ◽  
Temperature Dependent ◽  
Stress Strain ◽  
Proposed Model ◽  
Single Temperature ◽  
Testing Data ◽  
Bonded Composite ◽  
Tension And Compression

This study develops a general temperature-dependent stress–strain constitutive model for polymer-bonded composite materials, allowing for the prediction of deformation behaviors under tension and compression in the testing temperature range. Laboratory testing of the material specimens in uniaxial tension and compression at multiple temperatures ranging from −40 ∘C to 75 ∘C is performed. The testing data reveal that the stress–strain response can be divided into two general regimes, namely, a short elastic part followed by the plastic part; therefore, the Ramberg–Osgood relationship is proposed to build the stress–strain constitutive model at a single temperature. By correlating the model parameters with the corresponding temperature using a response surface, a general temperature-dependent stress–strain constitutive model is established. The effectiveness and accuracy of the proposed model are validated using several independent sets of testing data and third-party data. The performance of the proposed model is compared with an existing reference model. The validation and comparison results show that the proposed model has a lower number of parameters and yields smaller relative errors. The proposed constitutive model is further implemented as a user material routine in a finite element package. A simple structural example using the developed user material is presented and its accuracy is verified.

scholarly journals Temperature-Dependent Stiffening and Inelastic Behavior of Newly Synthesized Fiber-Reinforced Super Flexible Silica Aerogels

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2878
Author(s):  
Ameya Rege ◽  
Pascal Voepel ◽  
Emrah Okumus ◽  
Markus Hillgärtner ◽  
Mikhail Itskov ◽  
...  
Keyword(s):  
Silica Aerogels ◽  
Fiber Types ◽  
Static Tension ◽  
Inelastic Behavior ◽  
Temperature Dependent ◽  
Acoustic Insulation ◽  
Tension And Compression ◽  
Synthesis Procedure ◽  
Strength And Durability ◽  
Significant Attention

In recent years, flexible silica aerogels have gained significant attention, owing to their excellent thermal and acoustic insulation properties accompanied by mechanical flexibility. Fiber reinforcement of such aerogels results in a further enhancement of the strength and durability of the composite, while retaining the excellent insulation properties. In this paper, the influence of four different kinds of fibers within a flexible silica aerogel matrix is studied and reported. First, a description of the synthesis procedure and the resulting morphology of the four aerogel composites is presented. Their mechanical behavior under uniaxial quasi-static tension and compression is investigated, particularly their performance under uniaxial compression at different temperature conditions (50 °C, 0 °C, and −50 °C). The reinforcement of the flexible silica aerogels with four different fiber types only marginally influences the thermal conductivity but strongly enhances their mechanical properties.

High Temperature Nanoindentation for the Study of Flow Defects

2004 ◽  
Vol 841 ◽  
Author(s):  
C. A. Schuh ◽  
J. K. Mason ◽  
A. C. Lund ◽  
A. M. Hodge
Keyword(s):  
Metallic Glasses ◽  
Recent Progress ◽  
Activation Volume ◽  
Shear Bands ◽  
Discrete Events ◽  
Temperature Dependent ◽  
Crystalline Materials ◽  
Plasticity Problem ◽  
Incipient Plasticity ◽  
Nucleation Of Dislocations

ABSTRACTOur recent progress in elevated temperature nanoindentation is reviewed, with an emphasis on the study of discrete events (i.e., pop-in phenomena) observed during nanoindentation. For crystalline materials the incipient plasticity problem is associated with the nucleation of dislocations, an effect which we show to be significantly temperature dependent. For metallic glasses it is the operation of individual shear bands beneath the indenter that gives rise to pop-in events; here we also show this to be a temperature dependent phenomenon. Approaches to extract the activation volume and energy of defects involved in plastic flow beneath the indenter are also briefly described.

Theoretical prediction of temperature dependent shear modulus of bulk metallic glasses

2017 ◽  
Vol 91 ◽  
pp. 86-89 ◽  
Author(s):  
Xianhe Zhang ◽  
Weiguo Li ◽  
Ying Li ◽  
Jianzuo Ma ◽  
Yong Deng ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Theoretical Prediction ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Temperature Dependent

scholarly journals Strength criterion and temperature dependent strength model of metallic glasses

2019 ◽  
Vol 163 ◽  
pp. 242-251 ◽  
Author(s):  
Xianhe Zhang ◽  
Weiguo Li ◽  
Yong Deng ◽  
Jiaxing Shao ◽  
Xuyao Zhang ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Strength Criterion ◽  
Strength Model ◽  
Temperature Dependent

A constitutive theory and modeling on deviation of shear band inclination angles in bulk metallic glasses

2009 ◽  
Vol 24 (8) ◽  
pp. 2688-2696 ◽  
Author(s):  
Ming Zhao ◽  
Mo Li
Keyword(s):  
Shear Band ◽  
Inclination Angle ◽  
Metallic Glasses ◽  
Constitutive Models ◽  
Constitutive Theory ◽  
Free Volume Theory ◽  
Plane Strain Tension ◽  
Volume Dilatation ◽  
Inclination Angles ◽  
Tension And Compression

A constitutive theory for metallic glasses is established that is based mainly on the Drucker-Prager model and a free-volume theory. The primary emphasis of this theory is on volume dilatation and its consequences on mechanical responses in metallic glasses that have been known from studies in both experiments and atomistic simulations. We also implemented the constitutive theory in a finite element modeling scheme and conducted numerical modeling of deformation of a metallic glass under plane-strain tension and compression. In particular, we focused our attention on the deviation of the shear band inclination angle, a commonly observed phenomenon for metallic glasses. We found very good qualitative agreement with available experimental data on shear band inclination angle and stress-strain relation. We also give a detailed discussion on different constitutive models, in particular the Coulomb-Mohr model, in the context of predicting the shear band inclination angle.

Fracture Toughness of Amorphous Metals and Composites

2002 ◽  
Vol 754 ◽  
Author(s):  
J.J. Lewandowski ◽  
A.K. Thurston ◽  
P. Lowhaphandu
Keyword(s):  
Fracture Toughness ◽  
Metallic Glasses ◽  
Shear Banding ◽  
Notch Toughness ◽  
Body Centered Cubic ◽  
Temperature Dependent ◽  
Notch Radius ◽  
Glass Composites ◽  
Planar Crack ◽  
Crack Bifurcation

ABSTRACTThe effects of changes in notch radius on the toughness of two different Zr-based bulk metallic glasses have been determined. It is shown that increases in notch radius produce large increases to the toughness, accompanied by extensive shear banding and crack bifurcation. The fracture toughness of twenty (20) fatigue precracked specimens exhibiting planar crack growth were in the range 20.3 ± 6.7 MPa√m for the two Zr-based glasses. Increasing the notch radius to 110 μm produced notch toughness in the range 95.3 ± 8.3 MPa√m for nine (9) tests on Vitreloy I, well in excess of that typically observed in most structural materials. Toughness tests conducted on two fatigue precracked specimens of Vitreloy I at 77 K produced values for fracture toughness that were in the range 17.9 ± 2.7 MPa√m, similar to that obtained at 298 K. The fatigue precracked fracture toughness of metallic glass composites containing large crystalline regions of a body centered cubic Zr-Ti-Nb alloy were in the range 29–42 MPa√m, but the values were temperature dependent over the range 148 K to 500 K. Fracture surfaces were analyzed via Scanning Electron Microscopy (SEM).

scholarly journals Temperature-Dependent Mechanical Property of Zr-Based Metallic Glasses

2007 ◽  
Vol 48 (7) ◽  
pp. 1752-1754 ◽  
Author(s):  
Hongqi Li ◽  
Cang Fan ◽  
Hahn Choo ◽  
Peter K. Liaw
Keyword(s):  
Mechanical Property ◽  
Metallic Glasses ◽  
Temperature Dependent
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