DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Uniaxial, Pure Bending, and Column Buckling Experiments on Superelastic NiTi Rods and Tubes

Abstract

Many existing shape memory alloy (SMA) devices consist of slender beams and frames. To better understand SMA beam behavior, we experimentally examined the isothermal, room temperature response of superelastic NiTi rods and tubes, of similar outer diameters, subjected to four different modes of loading. Pure tension, pure compression, and pure bending experiments were first performed to establish and compare the baseline uniaxial and bending behaviors of rods and tubes. Column buckling experiments were then performed on rod and tube columns of several slenderness ratios to investigate their mechanical responses, phase transformation kinetics under combined uniaxial and bending deformation, and the interaction between material and structural instabilities. In all experiments, stereo digital image correlation measured local displacement fields in order to capture phenomena such as strain localization and propagating phase boundaries. Superelastic mechanical behavior and the nature of stress-induced phase transformation were found to be strongly affected by specimen geometry and the deformation mode. Under uniaxial tension, both the rod and tube had well-defined loading and unloading plateaus in their superelastic responses, during which stress-induced phase transformation propagated along the length of the specimen in the form of a high/low strain front. Due to the dependence of strain localization on kinematicmore » compatibility, the high/low strain front morphologies differed between the rod and tube: for the rod, the high/low strain front consisted of a diffuse “neck”, while the high/low strain front in the tube consisted of distinct, criss-crossing “fingers.” During uniaxial compression, both cross-sectional forms exhibited higher transformation stresses and smaller transformation strains than uniaxial tension, highlighting the now well-known tension-compression asymmetry of SMAs. Additionally, phase transformation localization and propagation were absent under compressive loading. During pure bending, the moment-curvature response of both forms exhibited plateaus and strain localization during forward and reverse transformations. Rod specimens developed localized, high-curvature regions that propagated along the specimen axis and caused shear strain near the high/low curvature interface; whereas, the tube specimens exhibited finger/wedge-like high strain regions over the tensile side of the tube which caused nonlinear strain profiles through the thickness of the specimen that did not propagate. Here, it was therefore found that classical beam theory assumptions did not hold in the presence of phase transformation localization (although, the assumptions did hold on average for the tube). During column buckling, the structures were loaded into the post-buckling regime yet recovered nearly-straight forms upon unloading. Strain localization was observed only for high aspect ratio (slender) tubes, but the mechanical responses were similar to that of rods of the same slenderness ratio. Also, an interesting “unbuckling” phenomenon was discovered in certain low aspect ratio (stout) columns, where late post-buckling straightening was observed despite continuous monotonic loading. Thus, these behaviors are some of the challenging phenomena which must be captured when developing SMA constitutive models and executing structural simulations.« less

Authors:
 [1];  [2];  [3];  [1]
  1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  3. Univ. of California, Santa Barbara, CA (United States). Dept. of Mechanical Engineering
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF); USDOD; US Air Force Office of Scientific Research (AFOSR)
OSTI Identifier:
1432476
Report Number(s):
SAND-2018-3151J
Journal ID: ISSN 0020-7683; 661754
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Accepted Manuscript
Journal Name:
International Journal of Solids and Structures
Additional Journal Information:
Journal Volume: 146; Journal ID: ISSN 0020-7683
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SMA; beam; buckling; bending; tension; compression; experiment; rod; tube; NiTi; superelastic

Citation Formats

Watkins, Ryan T., Reedlunn, Benjamin, Daly, Samantha, and Shaw, John A. Uniaxial, Pure Bending, and Column Buckling Experiments on Superelastic NiTi Rods and Tubes. United States: N. p., 2018. Web. doi:10.1016/j.ijsolstr.2018.01.037.
Watkins, Ryan T., Reedlunn, Benjamin, Daly, Samantha, & Shaw, John A. Uniaxial, Pure Bending, and Column Buckling Experiments on Superelastic NiTi Rods and Tubes. United States. https://doi.org/10.1016/j.ijsolstr.2018.01.037
Watkins, Ryan T., Reedlunn, Benjamin, Daly, Samantha, and Shaw, John A. Fri . "Uniaxial, Pure Bending, and Column Buckling Experiments on Superelastic NiTi Rods and Tubes". United States. https://doi.org/10.1016/j.ijsolstr.2018.01.037. https://www.osti.gov/servlets/purl/1432476.
@article{osti_1432476,
title = {Uniaxial, Pure Bending, and Column Buckling Experiments on Superelastic NiTi Rods and Tubes},
author = {Watkins, Ryan T. and Reedlunn, Benjamin and Daly, Samantha and Shaw, John A.},
abstractNote = {Many existing shape memory alloy (SMA) devices consist of slender beams and frames. To better understand SMA beam behavior, we experimentally examined the isothermal, room temperature response of superelastic NiTi rods and tubes, of similar outer diameters, subjected to four different modes of loading. Pure tension, pure compression, and pure bending experiments were first performed to establish and compare the baseline uniaxial and bending behaviors of rods and tubes. Column buckling experiments were then performed on rod and tube columns of several slenderness ratios to investigate their mechanical responses, phase transformation kinetics under combined uniaxial and bending deformation, and the interaction between material and structural instabilities. In all experiments, stereo digital image correlation measured local displacement fields in order to capture phenomena such as strain localization and propagating phase boundaries. Superelastic mechanical behavior and the nature of stress-induced phase transformation were found to be strongly affected by specimen geometry and the deformation mode. Under uniaxial tension, both the rod and tube had well-defined loading and unloading plateaus in their superelastic responses, during which stress-induced phase transformation propagated along the length of the specimen in the form of a high/low strain front. Due to the dependence of strain localization on kinematic compatibility, the high/low strain front morphologies differed between the rod and tube: for the rod, the high/low strain front consisted of a diffuse “neck”, while the high/low strain front in the tube consisted of distinct, criss-crossing “fingers.” During uniaxial compression, both cross-sectional forms exhibited higher transformation stresses and smaller transformation strains than uniaxial tension, highlighting the now well-known tension-compression asymmetry of SMAs. Additionally, phase transformation localization and propagation were absent under compressive loading. During pure bending, the moment-curvature response of both forms exhibited plateaus and strain localization during forward and reverse transformations. Rod specimens developed localized, high-curvature regions that propagated along the specimen axis and caused shear strain near the high/low curvature interface; whereas, the tube specimens exhibited finger/wedge-like high strain regions over the tensile side of the tube which caused nonlinear strain profiles through the thickness of the specimen that did not propagate. Here, it was therefore found that classical beam theory assumptions did not hold in the presence of phase transformation localization (although, the assumptions did hold on average for the tube). During column buckling, the structures were loaded into the post-buckling regime yet recovered nearly-straight forms upon unloading. Strain localization was observed only for high aspect ratio (slender) tubes, but the mechanical responses were similar to that of rods of the same slenderness ratio. Also, an interesting “unbuckling” phenomenon was discovered in certain low aspect ratio (stout) columns, where late post-buckling straightening was observed despite continuous monotonic loading. Thus, these behaviors are some of the challenging phenomena which must be captured when developing SMA constitutive models and executing structural simulations.},
doi = {10.1016/j.ijsolstr.2018.01.037},
journal = {International Journal of Solids and Structures},
number = ,
volume = 146,
place = {United States},
year = {Fri Mar 23 00:00:00 EDT 2018},
month = {Fri Mar 23 00:00:00 EDT 2018}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 19 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Tensile instability of initially spherical balloons
journal, January 1971


Localization in NiTi tubes under bending
journal, March 2014


Bending of Superelastic Wires, Part I: Experimental Aspects
journal, June 1995


Superelastic tension and bending characteristics of shape memory alloys
journal, July 2000

  • Bundara, B.; Tokuda, M.; Kuselj, B.
  • Metals and Materials, Vol. 6, Issue 4
  • DOI: 10.1007/BF03028074

Thermodynamics of Shape Memory Alloy Wire: Modeling, Experiments, and Application
journal, May 2006

  • Chang, Bi-Chiau; Shaw, John A.; Iadicola, Mark A.
  • Continuum Mechanics and Thermodynamics, Vol. 18, Issue 1-2
  • DOI: 10.1007/s00161-006-0022-9

Bifurcation to pear-shaped equilibria of pressurized spherical membranes
journal, January 1991


On equilibrium domains in superelastic NiTi tubes — helix versus cylinder
journal, May 2012


An overview of nitinol medical applications
journal, December 1999


Equilibrium of bars
journal, November 1975


The role of texture in tension–compression asymmetry in polycrystalline NiTi
journal, March 1999


Tension/torsion tests of pseudoelastic, polycrystalline NiTi shape memory alloys under temperature control
journal, May 2008


Underlying material response for Lüders-like instabilities
journal, August 2013


Post-bifurcation of perfect and imperfect spherical elastic membranes
journal, January 1980


Wrinkling Behavior of Highly Stretched Rectangular Elastic Films via Parametric Global Bifurcation
journal, April 2013

  • Healey, Timothy J.; Li, Qingdu; Cheng, Ron-Bin
  • Journal of Nonlinear Science, Vol. 23, Issue 5
  • DOI: 10.1007/s00332-013-9168-3

Non-medical applications of shape memory alloys
journal, December 1999


An Experimental Setup for Measuring Unstable Thermo-Mechanical Behavior of Shape Memory Alloy Wire
journal, February 2002

  • Iadicola, Mark A.; Shaw, John A.
  • Journal of Intelligent Material Systems and Structures, Vol. 13, Issue 2-3
  • DOI: 10.1177/104538902761402558

Rate and thermal sensitivities of unstable transformation behavior in a shape memory alloy
journal, April 2004


Buckling and recovery of NiTi tubes under axial compression
journal, February 2016


Martensite Strain Memory in the Shape Memory Alloy Nickel-Titanium Under Mechanical Cycling
journal, December 2010


The initiation and propagation of a localized instability in an inflated elastic tube
journal, January 1991


The initiation and growth of macroscopic martensite band in nano-grained NiTi microtube under tension
journal, November 2002


Lateral-torsional buckling of beams and the Southwell plot
journal, December 2002


Stretch-induced wrinkling of polyethylene thin sheets: Experiments and modeling
journal, May 2014


In-plane compressive response and crushing of honeycomb
journal, October 1994


In-plane crushing of a polycarbonate honeycomb
journal, January 1998


Buckling and postbuckling characteristics of the superelastic SMA columns
journal, December 2001

  • Rahman, Muhammad Ashiqur; Qiu, Jinhao; Tani, Junji
  • International Journal of Solids and Structures, Vol. 38, Issue 50-51
  • DOI: 10.1016/S0020-7683(01)00160-3

Tension, compression, and bending of superelastic shape memory alloy tubes
journal, February 2014

  • Reedlunn, Benjamin; Churchill, Christopher B.; Nelson, Emily E.
  • Journal of the Mechanics and Physics of Solids, Vol. 63
  • DOI: 10.1016/j.jmps.2012.12.012

Tips and Tricks for Characterizing Shape Memory Wire Part 5: Full-Field Strain Measurement by Digital Image Correlation
journal, May 2011


Pseudoelastic behaviour of shape memory alloy beams under pure bending: experiments and modelling
journal, April 2002


Finite-Element Simulation of the Anti-Buckling-Effect of a Shape Memory Alloy Bar
journal, July 2011

  • Richter, Frank; Kastner, Oliver; Eggeler, Gunther
  • Journal of Materials Engineering and Performance, Vol. 20, Issue 4-5
  • DOI: 10.1007/s11665-010-9797-8

Some Thoughts on the Southwell Plot
journal, December 1967


Inelastic Column Theory
journal, May 1947

  • Shanley, F. R.
  • Journal of the Aeronautical Sciences, Vol. 14, Issue 5
  • DOI: 10.2514/8.1346

Thermomechanical aspects of NiTi
journal, August 1995


On the nucleation and propagation of phase transformation fronts in a NiTi alloy
journal, February 1997


Initiation and propagation of localized deformation in elasto-plastic strips under uniaxial tension
journal, December 1997


On the applicability of the Southwell plot to plastic buckling
journal, June 1989


The Southwell Method for Predicting Plastic Buckling Loads for Elbows
journal, February 1983

  • Sobel, L. H.
  • Journal of Pressure Vessel Technology, Vol. 105, Issue 1
  • DOI: 10.1115/1.3264236

Applications of shape memory alloys in civil structures
journal, July 2006


Phase transformation in superelastic NiTi polycrystalline micro-tubes under tension and torsion––from localization to homogeneous deformation
journal, June 2002


Unbuckling of superelastic shape memory alloy columns
journal, January 2018

  • Watkins, Ryan T.; Shaw, John A.
  • Journal of Intelligent Material Systems and Structures, Vol. 29, Issue 7
  • DOI: 10.1177/1045389X17733331

Experimental study on rate dependence of macroscopic domain and stress hysteresis in NiTi shape memory alloy strips
journal, December 2010


Works referencing / citing this record:

Quantification of Uncertainties on the Critical Buckling Load of Columns under Axial Compression with Uncertain Random Materials
journal, June 2019

  • Ly, Hai-Bang; Desceliers, Christophe; Minh Le, Lu
  • Materials, Vol. 12, Issue 11
  • DOI: 10.3390/ma12111828

Quantification of Uncertainties on the Critical Buckling Load of Columns under Axial Compression with Uncertain Random Materials
journal, June 2019

  • Ly, Hai-Bang; Desceliers, Christophe; Minh Le, Lu
  • Materials, Vol. 12, Issue 11
  • DOI: 10.3390/ma12111828