Broad Range Of Strain Rates Research Articles

Dynamic mechanical response, energy absorption capacity, and constitutive modeling of polypropylene fiber-reinforced foamed concrete under high temperature

This study utilized a modified split Hopkinson pressure bar apparatus to subject polypropylene fiber-reinforced foamed concrete (PPFRFC) to substantial deformation loading at high temperatures and strain rates. Based on experimental results, the study systematically investigated the coupled effects of temperature and strain rate on the dynamic mechanical behavior of PPFRFC across a broad range of strain rates (0.001 s−1 to 1300 s−1) and temperatures (25 °C–600 °C). The findings revealed that elevated temperatures significantly affected various mechanical parameters including peak stress, plateau stress, elastic modulus, densification strain, dynamic increase factor (DIF), and energy absorption. Notably, with increasing temperature, the strain rate amplified the peak stress, plateau stress, and energy absorption, whereas its influence on the elastic modulus diminished. Microstructural examination revealed the absence of notable cracks in the pore walls after high-temperatures exposure. However, degradation of the cement matrix results in a loose skeleton structure within the pore walls, leading to a considerable reduction in material strength. Finally, a constitutive model was developed, considering the coupling effects of temperature and strain rate. This model accurately describes the mechanical response of the PPFRFC across various stages, including the elastic, plateau, and densification stages, as well as the stress drop behavior in the transition stage. Moreover, it effectively reflects the influence of strain rate and temperature coupling effects on the material's mechanical properties.

Numerical prediction of mechanical behavior of acrylonitrile-butadiene-styrene under three-point bending and impact loadings by Anand–Gurtin material model

A satisfactory reproduction of three-point bending and impact test data of an industrially important amorphous polymer, acrylonitrile-butadiene-styrene (ABS), in the context of finite element analysis is of prime importance to industry. Constitutive material models developed for amorphous polymers are capable of describing their complex mechanical behavior under multiaxial loadings with a variety of success; therefore, the computational accuracy directly depends on the selection of constitutive model and a proper determination of its associated parameters. Thus, this study aimed at accurately predicting the multiaxial mechanical behavior of ABS by the Anand–Gurtin elastic–viscoplastic material model selected as the constitutive model and employed for the first time in the numerical implementations of the three-point bending and impact tests of ABS. To this end, the constitutive model parameters never identified for ABS before was first determined mainly depending on uniaxial compression test data at various strain rates ranging from 2 × 10−4 s−1 to 2 × 10−1 s−1 and then validated against tension test data for a broad range of strain rates varying from 1 × 10−3 s−1 to 45 s−1. All the experimental data taken into consideration in this study was taken from the previous studies of authors. The material model with the validated constitutive parameters of ABS was utilized in the numerical implementation of three-point bending tests for two different bending speeds (0.05–10 mm/s), in addition, impact tests for two various low impact velocities (4.43–6.23 m/s). Numerical results revealed that the constitutive model successfully reproduces the three-point bending test data of ABS for both bending speeds but acceptably overestimates the impact response of ABS under both low impact velocities in terms of peak impact load. Hence, it was concluded that this computationally inexpensive complex material model with the constitutive parameters determined for ABS can be used in the accurate prediction of its multiaxial material behavior.

Small-scale deformation behaviour of the AlCoCrFeNi2.1 eutectic high entropy alloy

ABSTRACT Novel methods to probe and evaluate the mechanical properties of High entropy alloy are gaining popularity to accelerate the development of new material for structural application and for establishing the physics-based mechanical property models. Nanoindentation techniques are predominantly suitable for evaluating the properties of materials in which deformation volumes can be cautiously controlled, and indentation can be applied to probe the properties of specific phases or features present within the microstructure. The current investigation is based on the plastic deformation response of Eutectic High Entropy Alloy, AlCoCrFeNi2.1, using experimental and computational approaches. In this paper, the plastic deformation of eutectic high entropy alloy AlCoCrFeNi2.1 is investigated using nanoindentation over a broad range of strain rates at room temperature to probe the mechanical properties of Eutectic High Entropy Alloy, AlCoCrFeNi2.1 and also to understand its elasto-plastic behaviour of BCC and FCC phase present in the alloy. In order to capture the deformation mechanism of material under the tip of the nano-indenter as well as to predict the load variation with depth, molecular dynamic simulation is performed. A characteristic load-depth curve has also been generated from the developed model, which is in good agreement with the experimental one. These findings will lead to understanding the phase-specific contribution to bulk mechanical response of multicomponent alloys and aid in designing structural materials with high fracture toughness.

Strain rate induced toughening of individual collagen fibrils.

The nonlinear mechanical behavior of individual nanoscale collagen fibrils is governed by molecular stretching and sliding that result in a viscous response, which is still not fully understood. Toward this goal, the in vitro mechanical behavior of individual reconstituted mammalian collagen fibrils was quantified in a broad range of strain-rates, spanning roughly six orders of magnitude, from 10-4 to 35 s-1. It is shown that the nonlinear mechanical response is strain rate sensitive with the tangent modulus in the linear deformation regime increasing monotonically from 214 ± 8 to 358 ± 11 MPa. More pronounced is the effect of the strain rate on the ultimate tensile strength that is found to increase monotonically by a factor of four, from 42 ± 6 to 160 ± 14 MPa. Importantly, fibril strengthening takes place without a reduction in ductility, which results in equivalently large increase in toughness with the increasing strain rate. This experimental strain rate dependent mechanical response is captured well by a structural constitutive model that incorporates the salient features of the collagen microstructure via a process of gradual recruitment of kinked tropocollagen molecules, thus giving rise to the initial "toe-heel" mechanical behavior, followed by molecular stretching and sustained intermolecular slip that is initiated at a strain rate dependent stress threshold. The model shows that the fraction of tropocollagen molecules undergoing straightening increases continuously during loading, whereas molecular sliding is initiated after a small fibril strain (1%-2%) and progressively increases with applied strain.

Predicting extreme anisotropy and shape variations in impact testing of tantalum single crystals

Recent Taylor cylinder impact tests carried out for Ta single crystals showed strong variations in dimensional changes for different crystallographic directions aligned with the cylindrical axis. In order to capture the effect of crystallography on the deformation characteristics and final shapes of the impacted cylinders, a single crystal material subroutine is adapted and embedded in the solid mechanics/dynamics Finite Element solver Abaqus to simulate the aforementioned single crystal Ta Taylor impact experiments. Details of the coupled model implementation, and insights on the role played by single crystal anisotropic flow on the deformation behavior across a broad range of strain rates and temperatures for different single crystal orientations are presented and discussed. We demonstrate the predictive capability of the adopted crystal plasticity model to capture the significant role played by crystal orientation-induced anisotropy, as well as strain hardening and adiabatic heating, on the dynamic deformation response of crystalline materials. This re-emphasizes the need of microstructure-aware models to improve the accuracy of simulations for high-consequence engineering design.

Effect of Microstructure on the Johnson-Cook Constitutive Model Parameters of Ti-6Al-4V Alloy

Constitutive models are widely used to predict the mechanical behavior of materials. In this research, the Johnson-Cook (J-C) constitutive model parameters of Ti-6Al-4V (Ti64) alloy with different microstructural details were fitted based on the mechanical properties over a broad range of strain rates and temperatures. The results indicate that the microstructural details have a significant effect on the mechanical properties and the J-C model parameters of Ti64. The five material parameters (A, B, n, C, m) in J-C model of Ti64 exhibit completely different varying trends as a function of the equiaxed primary α-phase volume fraction and α-platelet thickness. These changes in J-C model parameters of Ti64 can be attributed to the effect of microstructural details on the dislocation nucleation and motion under different deformation conditions.

Experimental verification of a crystal plasticity-based simulation framework for predicting microstructure and geometric shape changes: Application to bending and Taylor impact testing of Zr

This paper is concerned with experimental verification of a recently developed multi-scale simulation framework for plastic deformation of metallic materials from quasi-static to impact deformation conditions. The framework is a visco-plastic self-consistent (VPSC) polycrystalline model embedded in an implicit finite element method (FE-VPSC) to provide a microstructure-sensitive constitutive response at each material point. Each material point of the FEM model is a polycrystalline aggregate with crystallographic deformation mechanisms operating at the single crystal scale with their evolving activity based on a dislocation density-based hardening law and texture. Four beams and three cylinders machined in different orientations from a textured plate of high-purity zirconium are tested quasi-statically in 4-point bending and at speeds of 100 m/s, 170 m/s and 243 m/s during Taylor impact tests, respectively. The variation in dimensional changes resulting from different sample orientations in the plate with respect to loading directions is measured for each sample. Moreover, texture and twinning characterization is performed using electron backscattered diffraction (EBSD). The deformation processes and underlying evolution of microstructure are successfully simulated using the FE-VPSC framework. In doing so, the model parameters are optimized and validated across a broad range of strain rates and temperatures. Simulation results in terms of geometrical changes and microstructural evolution are compared with the experimental measurements. The model predicts anisotropic material flow resulting from the hard-to-deform crystallographic directions, the development of gradients in texture and twinning through the geometries, tension–compression asymmetry, as well as the extent of plasticity under impact.

Mechanical behavior and texture evolution of WE43 magnesium-rare earth alloy in Split-Hopkinson Pressure Bar and Taylor Impact Cylinder Testing

Mechanical behavior and texture evolution of Mg rare-earth alloy WE43 is investigated for strain-rates 10−3/s to upwards of 105/s for the two material conditions - as-cast (AC) and T6 age hardened, rolled plate (RT6). The high strain-rate behavior is tested using both Taylor cylinder impact tests (TC) and split Hopkinson pressure bar tests (SHB) and bulk textures are obtained using neutron diffraction. Unlike the quasi-static strained material, AC and RT6 SHB retained high hardening rates throughout the test, even up to 30% true strain. Moreover, the high strain-rate data revealed that the RT6 material has a much higher strength than the AC material, but similar hardening rates despite significantly different initial texture. The flow stress near yield increased up to 10% for RT6 and up to 30% for AC as the strain-rate increased six orders of magnitude from quasi-static rates 10−3/s to 103/s. Neither material exhibited significant plastic anisotropy over the broad range of strain rates, despite the fact that the RT6 material had a moderately strong initial texture. In the TC tests, the geometric cross-sectional changes and texture along the cylinder from the cylindrical sample foot to head are measured and from the neutron diffraction texture analysis, upper-bound estimates of twin volume fraction are obtained as well as dislocation density from analyzing diffraction peak broadening. Recorded geometrical changes along several loading directions show that the material has deformed homogeneously under impact. Analysis of deformed textures indicates that {101¯2} extension deformation twinning occurred in the RT6 condition over the range of strain rates, with an upper bound estimate of 40% twin volume fraction for approximately 0.10-0.25 true strain. The peak texture components after the impact have their c-axes closely aligned with the impact direction. These observations are presented and rationalized in the paper.

High Strain Rate Compressive Behavior of As-Cast and Heat Treated Magnesium-Rare Earth Alloy at Low Temperatures

The deformation behavior and mechanical properties of magnesium-rare earth alloy (WE43) were investigated for as-cast and heat-treated conditions at a broad range of strain rates and temperatures. The study was focused on developing a constitutive relation for the alloy with respect to temperature and strain rate for the as-cast and heat treated conditions. The experimental results show higher strength of the alloy at lower temperatures. Heat treatment of the alloy has a remarkable effect on the alloy microstructure, where eutectic mixture dissolves and only rare earth rich precipitates are observed in the heat treated microstructure. This change in the microstructure was reflected in the measured tensile properties and heat treated alloy has higher strength due to strengthening effect of the fine precipitates. A constitutive model was established to describe the thermo-viscoplastic flow behavior of the hexagonal close-packed alloy in a broad range of coupled strain rates (0.0001/s–3055/s) and temperatures (77–296 K). The model predictions agree with the experimental results at both quasi-static and high strain rates. The results show the possibility of extending this work to develop time–temperature superposition procedures using the coupling parameters identified by the model.

Tolerable ranges of fluid shear for early life-stage fishes: implications for safe fish passage at hydropower and irrigation infrastructure

Egg and larval fish drifting downstream are likely to encounter river infrastructure leading to mortality. Elevated fluid shear is one likely cause. To confirm this and determine tolerable strain rates resulting from fluid shear, egg and larvae of three Australian species were exposed to a high-velocity, submerged jet in a laboratory flume. Mortality was modelled over a broad range of strain rates, allowing critical thresholds to be estimated. Eggs were very susceptible to mortality at low strain rates and 100% of golden and silver perch died once strain rate exceeded 629 and 148s–1 respectively. Larvae were less vulnerable than eggs, but mortality increased at higher strain rates and at younger ages. Most ages of larvae will be protected if strain rate does not exceed 600s–1, although a lower guideline of less than 400s–1 may be needed in areas where very early stage Murray cod larvae drift. Golden perch and silver perch were not susceptible to shear once maturity reached ~25 days post-hatch (nearing juvenile metamorphosis). The thresholds described here will prove useful when refining design and operational guidelines for hydropower and irrigation infrastructure to improve fish survival.

Influence of stress triaxiality on the failure behavior of Ti-6Al-4V alloy under a broad range of strain rates

The plastic deformation and failure behavior of metals is significantly affected by loading conditions such as stress state, strain rate, temperature and etc. In this study, the tensile behavior of a dual-phase Ti-6Al-4V alloy was investigated and the influences of stress triaxiality, strain rate and temperature were characterized. Specimens with various initial stress triaxialities (0.33, 0.43, 0.52, 0.62, and 0.74 in this work) were designed and tested under quasi-static and dynamic tension. Digital image correlation (DIC) technique was used to accurately determine the local strain on the surface of the specimen during the process of deformation. Combined experimental-numerical method was adopted to acquire the maximum local strain as well as the local stress triaxiality. Results show that the critical point of the specimen always hides in the center of the cylinder and it is unpractical to measure these values directly, therefore calibration is required for both failure strain and stress triaxiality. Moreover, our results indicate that the flow stress of Ti-6Al-4V is significantly affected by the stress condition. The notched specimens display enhanced engineering flow stress (or load capacity) compared with the smooth cylinder. On the contrary, after calibrated by Bridgman’s theory, their true equivalent stresses are actually lower. These findings remind the researchers that special attention should be paid to the effects of stress triaxiality, even the general trend might be wrong.

Toward the constitutive modeling of epoxy matrix: Temperature-accelerated quasi-static molecular simulations consistent with the experimental test

Abstract We propose an efficient simulation-based methodology to characterize the quasi-static (experimental low strain rate) yield stress of an amorphous thermoset polymer, which has generally been considered a limitation of molecular dynamics (MD) simulations owing to the extremely short time steps involved. In an effort to overcome this limitation, the temperature-accelerated method – in which temperature is treated as being equivalent to time in deformation kinetics – is employed to explore the experimental strain rate conditions. The mechanical tensile behavior of a highly crosslinked polymer is then investigated with MD simulations by considering different strain rates and temperatures below the glass transition temperature. The derived yield stress represents the time- and temperature-dependent characteristics, showing that the yield stress decreases with increasing temperature and decreasing strain rate. Changeable vertical and horizontal shift factors are introduced for the first time to reflect nonlinear characteristics of the yield stress across a broad range of strain rates and to quantify the correlation between increasing temperatures and decreasing strain rates. With the proposed method, the Eyring plot, which describes the rate effect on yield from quasi-static to high-rate conditions, is predicted from MD simulations, and agrees well with macroscopic experimental results. From the constructed Eyring plot, the experimentally validated quasi-static stress-strain response is also estimated by using linear elastic model and Ludwick's hardening model. The proposed method provides new avenues for the design of glassy polymers using only fully atomistic MD simulations, thus overcoming the existing temporal scale limitations.

Mechanical Behavior of Two Ferrite–Martensite Dual-Phase Steels over a Broad Range of Strain Rates

The present study concerns the deformation and fracture behavior of two ferrite–martensite dual phase steels (FMDP660 and FMDP780) with different phase fractions subjected to different strain rate (0.001 s−1 to 1000 s−1) tensile testing. For both steels, the yield strength (YS) monotonically increased with strain rates, whereas the values of ultimate tensile strength (UTS), uniform elongation (UE) and post-uniform elongation (PUE) were maintained stable at the low strain rate range (0.001–0.1 s−1), followed by a significant increase with strain rate at high strain rate levels (0.1–1000 s−1). The FMDP780 steel with a higher fraction of martensite possessed a stronger strain rate sensitivity of tensile strength and elongation (UE and PUE) values at the high strain rate stage, compared with the FMDP660 sample. The change of UTS and UE with different strain rates and phase fractions was highly related to the strain hardening behavior, which was controlled by the dislocation multiplication in ferrite, as validated by transmission electron microscopy (TEM). The fracture surface of the two steels was characterized by dimpled-type fracture associated with microvoid formation at the ferrite–martensite interfaces, regardless of the strain rates. The change of the dimple size and PUE value of the two steels with strain rates was attributed to the effect of adiabatic heating during tensile testing.

Mechanical properties of silicone based composites as a temperature insensitive ballistic backing material for quantifying back face deformation

This paper describes a new witness material for quantifying the back face deformation (BFD) resulting from high rate impact of ballistic protective equipment. Accurate BFD quantification is critical for the assessment and certification of personal protective equipment, such as body armor and helmets, and ballistic evaluation. A common witness material is ballistic clay, specifically, Roma Plastilina No. 1 (RP1). RP1 must be heated to nearly 38°C to pass calibration, and used within a limited time frame to remain in calibration. RP1 also exhibits lot-to-lot variability and is sensitive to time, temperature, and handling procedures, which limits the BFD accuracy and reproducibility. A new silicone composite backing material (SCBM) was developed and tested side-by-side with heated RP1 using quasi-static indentation and compression, low velocity impact, spherical projectile penetration, and both soft and hard armor ballistic BFD measurements to compare their response over a broad range of strain rates and temperatures. The results demonstrate that SCBM mimics the heated RP1 response at room temperature and exhibits minimal temperature sensitivity. With additional optimization of the composition and processing, SCBM could be a drop-in replacement for RP1 that is used at room temperature during BFD quantification with minimal changes to the current RP1 handling protocols and infrastructure. It is anticipated that removing the heating requirement, and temperature-dependence, associated with RP1 will reduce test variability, simplify testing logistics, and enhance test range productivity.

Scalar dissipation rates in a turbulent partially-premixed dimethyl ether/air jet flame

This paper presents the gradient structure of a turbulent partially premixed dimethyl ether (DME)/air jet flame operating at a jet Reynolds number of 29,300. Temperature and mixture fraction profiles from Raman/Rayleigh/CO-LIF line measurements are used to determine one-dimensional scalar dissipation rates at six axial locations. A major focus of the current work is to assess the effects of experimental artifacts, including spatial resolution, noise, and dimensionality, on the accuracy of the derived scalar dissipation rate. Two-dimensional probability density functions (PDFs) of the mixture fraction gradients are used to determine possible clipping effects due to insufficient spatial resolution. This resolution limit is compared to values determined from one-dimensional dissipation spectra and scaling laws. Spatial resolution also is investigated using laminar flame calculations in conjunction with optical-blur filters representing the experimental setup. The impact of noise is treated by error propagation methods. Monte Carlo simulations and experimental data from laminar flames are used to verify and validate the models used to predict noise propagation for the measurements of the absolute gradients, squared gradients, and scalar dissipation rates. Gradient and scalar dissipation rate detection limits and contribution from apparent dissipation (due to noise effects) are presented as functions of measurement signal-to-noise ratios. A noised lognormal function is introduced to investigate the impact of noise on derived PDFs and corresponding statistical moments of the measured scalar gradients and the scalar dissipation rate within the turbulent flame. Results from the turbulent flame measurements are presented in the form of scatter plots and conditional statistics to examine turbulence-chemistry interaction and develop a database for model assessment. Specifically, the results are compared to laminar flame calculations over a broad range of strain rates with multi-component and unity Lewis number transport assumptions. This comparison is used to assess the relevance of differential diffusion effects on scalar dissipation rates in the turbulent flame.

Compressive responses of ultrafine-grained titanium within a broad range of strain rates and temperatures

Mechanical behavior of ultrafine-grained (UFG) materials is affected by many factors including “intrinsic” ones such as grain size, dislocation density and concentration of impurities, and “extrinsic” ones such as temperature, strain rate and strain. To evaluate those contributions to the yield and flow stress of commercial-purity titanium, compressive mechanical tests were conducted at strain rates from 10−4 to 3 × 103 s−1 and temperature from 77 to 473 K. Microstructure characterization was also carried out to pin-down the underlying mechanisms responsible for the observed mechanical behavior. Results show that the primary strengthening sources for coarse-grained (CG) titanium comes from interstitials, which contribute ∼64% of the yield stress. Grain boundary strengthening, dislocation interaction and interstitials contribute ∼38%, ∼32% and ∼30% of the yield stress of UFG-Ti, respectively. The flow stresses of both CG and UFG titanium depends positively on strain rate and negatively on temperature, but neither strain rate sensitivity (SRS) nor temperature sensitivity (TS) is constant over a wide range. The SRS of titanium is found to increase with increase in grain size and temperature.

Interactions of antioxidant supplementation and moderate exercise on brain function

In the present study, the work-softening transient behavior of a powder metallurgy Ti-47Al-2Nb-2Cr alloy during hot deformation, along with microstructure characterization under a temperature of 950–1150 °C and a broad range of strain rates encompassing 0.001–0.1 s− 1, has been investigated. The single peak characteristic, which appeared in all the true stress-strain curves, indicates that DRX is a dominating softening mechanism. Furthermore, it was found that grain boundary bulging played a primary role in the DRX nucleation mechanism through observation of the microstructure evolution. The DRX critical strain occurs at εc ≅ 0.73εp and the peak strain has been expressed through the Zener-Hollomon parameter. A mathematic model based on the Avrami equation has been established to describe the DRX behavior of the alloy, with the volume fractions of DRX grains calculated by the model in good agreement to that of the experimental results.

Dynamic softening behavior and microstructural characterization of TiAl-based alloy during hot deformation

In the present study, the work-softening transient behavior of a powder metallurgy Ti-47Al-2Nb-2Cr alloy during hot deformation, along with microstructure characterization under a temperature of 950–1150°C and a broad range of strain rates encompassing 0.001–0.1s−1, has been investigated. The single peak characteristic, which appeared in all the true stress-strain curves, indicates that DRX is a dominating softening mechanism. Furthermore, it was found that grain boundary bulging played a primary role in the DRX nucleation mechanism through observation of the microstructure evolution. The DRX critical strain occurs at εc≅0.73εp and the peak strain has been expressed through the Zener-Hollomon parameter. A mathematic model based on the Avrami equation has been established to describe the DRX behavior of the alloy, with the volume fractions of DRX grains calculated by the model in good agreement to that of the experimental results.

A master curve for the size and strain rate dependent large deformation behavior of PS nanofibers at room temperature

Unlike the nominally brittle behavior of bulk polystyrene (PS), PS nanofibers with particular combinations of molecular weight (MW) and submicron scale diameters exhibit stable necking followed by pronounced strain-hardening, resulting in simultaneous increase in strength and ductility. The ratio, Dnorm, of the fiber diameter, D, to the intrinsic macromolecular length scale described by the root-mean-square end-to-end chain distance, Ree ∼ MW, has been shown to be an effective scaling parameter to determine the initiation and evolution of necking and strain hardening in submicron scale unoriented PS fibers. In this study, the room temperature large deformation response of individual PS nanofibers is quantified for the first time over a broad range of strain rates between 10−4–102 s−1. It is shown that for all combinations of MW in the range 123,000–2,000,0000 g/mol and D in the range 200–750 nm that satisfy Dnorm < 10, an increasing strain rate results in monotonic increase of the stress amplitude without any reduction in the nanofiber stretch ratio to failure. Furthermore, the experimental stress vs. stretch ratio curves for Dnorm < 10 obeyed a multiplicative decomposition of stress into a shape and a rate component. This decomposition permits the construction of a normalized stress vs. strain master curve that captures well both the size effects, originating in the relative molecular and specimen length scales, and the strain rate effects on the mechanical behavior of PS nanofibers at room temperature.

The Influence of Strain Rate on the Tensile Properties of a Nb–Ti/Cu Superconducting Composite Wire Under Variable Cryogenic Temperature

The tensile properties of superconducting wires usually play an essential role in practical applications. The effect of strain rate on the tension responses of commercial superconducting composite wires consisting of niobium-47wt.% Ti filaments in a copper matrix (Nb-Ti/Cu) with a Cu:superconductor ratio of ~4.3, under variable cryogenic temperature, is experimentally investigated in this paper. A variable temperature cryostat system is employed, which provides the cooling environment from room temperature to liquid nitrogen temperature, and a compact-scale cryogenic-type extensometer is utilized to measure the tensile strains on the superconducting wires. Under a range of cryogenic temperatures, the corresponding stress and strains are recorded during the elongation of the wire with a broad range of strain rates (10 -1 to 10 -4 s -1 ). The cryogenic mechanical behaviors of the Nb-Ti/Cu composite wires, including the tensile strength and elongation at fracture, as well as the yield stress, are captured experimentally. It is shown that the ultimate tensile strength and the yield strength of the Nb-Ti/Cu superconducting wires increased linearly with cryogenic temperature for the lower strain rates, while notable nonlinear features appear at a higher strain rate. The elongations always increased nonlinearly with decreasing temperature for each tested strain rate, but the elongations decreased with higher strain rate. The Young's modulus approximately increases linearly with decreasing temperature for each strain rate. Additionally, the effect of strain hardening rate derived from the stress and strain relations for the superconducting wires at different cryogenic temperatures and strain rates is discussed.