Impact of ground motion duration on concrete shear walls reinforced with different types of shape memory alloy rebars

Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 2739-2754
Author(s):  
Emad Abraik ◽  
Jamal Assaf
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Ground Motion ◽  
Shear Walls ◽  
Different Types

Determination of Preferred Morphology of Self-Accommodating Martensite in Ti-Nb-Al Shape Memory Alloy Using Optical Microscopy

2014 ◽  
Vol 922 ◽  
pp. 260-263 ◽  
Author(s):  
Masatoshi Ii ◽  
Masaki Tahara ◽  
Hideki Hosoda ◽  
Shuichi Miyazaki ◽  
Tomonari Inamura
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Optical Microscopy ◽  
Early Stage ◽  
Type I ◽  
Type Ii ◽  
Different Types ◽  
Forward Transformation

The preferred morphology of self-accommodation (SA) microstructure in a Ti-Nb-Al shape memory alloy was investigated by the evaluation of the frequency distribution of the habit plane variant (HPV) clusters using in-situ optical microscopy. The observed HPV clusters were classified into two different types; one is the cluster connected by the {111}o type I twin (Type I) and the other is connected by the <211>o type II twin (Type II). The total fractions of the Type I and Type II clusters were 52% and 48%, respectively. The incompatibility at junction planes (JPs) of the two clusters was almost the same among these clusters. However, most of the larger martensite plates (> 50μm) formed Type I cluster at the later stage of the reverse martensitic transformation, i.e., at the early stage of the forward transformation upon cooling. The ratio of the fraction of Type I and II is almost 2:1 at the early stage of the forward transformation.

WRINKLING ATOP SHAPE MEMORY MATERIALS

2012 ◽  
Vol 19 (02) ◽  
pp. 1250010 ◽  
Author(s):  
L. SUN ◽  
Y. ZHAO ◽  
W. M. HUANG ◽  
H. PURNAWALI ◽  
Y. Q. FU
Keyword(s):  
Surface Tension ◽  
Surface Roughness ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Patterned Surfaces ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Shape Memory Materials ◽  
Processing Techniques

Many surface related properties, such as surface roughness, surface tension and reflection etc are heavily dependent on the surface morphology of materials. Patterned surfaces may have significant effects on these properties. In this paper, we compare wrinkles produced atop three different types of shape memory materials, namely, shape memory alloy, shape memory polymer and shape memory hybrid. We show the advantages and disadvantages of them in terms of the processing techniques and the resultant wrinkle patterns.

scholarly journals Cyclic Behavior of Masonry Shear Walls Retrofitted with Engineered Cementitious Composite and Pseudoelastic Shape Memory Alloy

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 511
Author(s):  
Alireza Tabrizikahou ◽  
Mieczysław Kuczma ◽  
Magdalena Łasecka-Plura ◽  
Ehsan Noroozinejad Noroozinejad Farsangi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shear Walls ◽  
Absorption Capacity ◽  
Cyclic Behavior ◽  
Masonry Walls ◽  
Cementitious Composite ◽  
Energy Absorption Capacity ◽  
Engineered Cementitious Composite ◽  
Mesh Density

The behavior of masonry shear walls reinforced with pseudoelastic Ni–Ti shape memory alloy (SMA) strips and engineered cementitious composite (ECC) sheets is the main focus of this paper. The walls were subjected to quasi-static cyclic in-plane loads and evaluated by using Abaqus. Eight cases of strengthening of masonry walls were investigated. Three masonry walls were strengthened with different thicknesses of ECC sheets using epoxy as adhesion, three walls were reinforced with different thicknesses of Ni–Ti strips in a cross form bonded to both the surfaces of the wall, and one was utilized as a reference wall without any reinforcing element. The final concept was a hybrid of strengthening methods in which the Ni–Ti strips were embedded in ECC sheets. The effect of mesh density on analytical outcomes is also discussed. A parameterized analysis was conducted to examine the influence of various variables such as the thickness of the Ni–Ti strips and that of ECC sheets. The results show that using the ECC sheet in combination with pseudoelastic Ni–Ti SMA strips enhances the energy absorption capacity and stiffness of masonry walls, demonstrating its efficacy as a reinforcing method.

Effectiveness of the shape memory alloy reinforcement in concrete coupled shear walls

2016 ◽  
Vol 28 (5) ◽  
pp. 640-652 ◽  
Author(s):  
Mehdi Ghassemieh ◽  
Moein Rezapour ◽  
Vahid Sadeghi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shear Walls ◽  
Shear Wall ◽  
Coupling Beams ◽  
Permanent Displacement ◽  
Finite Element Software ◽  
The Third ◽  
Superelastic Behavior ◽  
Concrete Damage

The use of shape memory alloys as a rebar in concrete structures has been receiving increasing attention among researchers. In this study, it is intended to evaluate the application of superelastic Nitinol in reducing the damage to the coupling beams and opening corners within a concrete shear wall. Abaqus finite element software was utilized to develop three verified coupled shear wall models. First, a model without diagonal and shape memory alloy rebars is developed to assess conventional shear walls with openings. Steel diagonal rebars are embedded in the coupling beams of the second model, and shape memory alloy diagonal rebars are embedded in the coupling beams of the third model. Shape memory alloy is also implemented in the opening corners of the third model. All models are subjected to cyclic loading to evaluate the concrete damage. Results indicated that the diagonal rebars reduced damage to the coupling beam and opening corners. The damages were the least when shape memory alloy diagonal rebars are utilized in the model. The superelastic behavior of the shape memory alloy also reduced permanent displacement of the shear wall subjected to substantial lateral loadings.

A new concept of isolation bearings for highway steel bridges using shape memory alloys

2005 ◽  
Vol 32 (5) ◽  
pp. 957-967 ◽  
Author(s):  
Eunsoo Choi ◽  
Tae-hyun Nam ◽  
Baik-Soon Cho
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Ground Motion ◽  
Residual Deformation ◽  
Steel Bridge ◽  
Ground Acceleration ◽  
Lead Rubber Bearings ◽  
Rubber Bearings ◽  
Isolation Device ◽  
Strong Ground

Conventional lead–rubber bearings (LRB) may have a problem of instability and unrecovered deformation with a strong ground motion. To improve the problems, this study proposed a new concept of an isolation device in which shape memory alloy wires were incorporated in an elastomeric bearing. This study illustrated the behavior of shape memory alloy in tension and discussed the variation of stiffness and stress on the hyteresis curves. A three-span continuous steel bridge was used for seismic analyses to compare the performance of lead–rubber bearings with the proposed bearings. This study showed that large residual deformation of LRB occurred even with a weak ground motion of peak ground acceleration (PGA) of 0.2g. The proposed bearings effectively limited the relative displacement of the deck when tested for the strong ground motions and almost recovered the original undeformed shape. However, the proposed bearing increases the demand on bridge columns compared with the LRB.Key words: shape memory alloy, lead–rubber bearings, seismic bridge analysis, isolation device, residual deformation.

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