Hardening Behavior Research Articles

Egocentric distance perception in older adults: Results from a functional magnetic resonance imaging and driving simulator study.

The ability to appropriately perceive distances in activities of daily living, such as driving, is necessary when performing complex maneuvers. With aging, certain driving behaviors and cognitive functions change; however, it remains unknown if egocentric distance perception (EDP) performance is altered and whether its neural activity also changes as we grow older. To that end, 19 young and 17 older healthy adults drove in a driving simulator and performed an functional magnetic resonance imaging (fMRI) experiment where we presented adults with an EDP task. We discovered that (a) EDP task performance was similar between groups, with higher response times in older adults; (b) older adults showed higher prefrontal and parietal activation; and (c) higher functional connectivity within frontal and parietal-occipital-cerebellar networks; and (d) an association between EDP performance and hard braking behaviors in the driving simulator was found. In conclusion, EDP functioning remains largely intact with aging, possibly due to an extended and effective rearrangement in functional brain resources, and may play a role in braking behaviors while driving.

Analysis of the Response of a Single Pile Using the Disturbance State Concept Theory

Based on disturbed state concept (DSC) theory, this paper reports an analysis of the progressive failure mechanism of a pile–soil system from a new perspective. Assuming that the strengths of the pile–soil interface elements and the soil elements at the pile end follow an exponential distribution, the load transfer models of skin friction and end resistance based on DSC theory are established, and the significance and value method of the parameters in the models are clarified. The analysis of the relevant parameters shows that the proposed DSC load transfer models can simulate the nonlinear hardening or softening behavior of skin friction and end resistance. Based on the proposed DSC load transfer models, a simple and efficient iterative calculation method for the analysis of the bearing behavior of a single pile is established. It is demonstrated from case studies that, compared with calculated results using other methods, the load–settlement curves at the pile head obtained from the method proposed in this paper are in better agreement with the measured values, and could reflect the skin friction and end resistance softening characteristics of the tested piles in a more realistic manner. Furthermore, a parametric study is carried out to analyze the influence of the relevant model parameters on the response of a single pile.

New chromium steel grade for creep applications

In this study, a novel Chromium steel grade (COIN2) is produced as a result of a new steel composition and an innovative heat treatment. This new steel grade COIN2 evolves from the P92 steel grade and other novel steel grade recently created by the authors (COIN), and represents an enhancement of hardness, tensile properties, and creep behaviour with respect to them, which validates the metallurgical strategy used for further research in order to increase the efficiency of power plants and thus reduce the CO2 emissions. The characterization reveals a significant property improvement with the innovative thermal treatment, contributing to the production of a novel and more competitive steel grade for creep applications.

Parameter Identification of Chaboche Model for Aluminum Alloy Sheets Based on Differential Evolution Algorithm

Springback prediction is one of the most challenging in finite element analysis for sheet metal forming processes. The demand requests the development of a kinematic hardening model and parameter identification. This study presents a schematic strategy to identify parameters of Chaboche’s kinematic hardening model based on a differential evolution optimization method. To this goal, several tension-compression (TC) tests were conducted to observe the Bauchinger’s effects and kinematic hardening behaviors of two aluminum alloy sheets: AA6022-T6 and AA7075-T76. A Python code is developed to apply the proposed method in identifying parameters of the kinematic hardening model. The calibrated material models were implemented in Abaqus software to simulate V-bending and U-bending tests for the investigated materials. The predictions for springback amount match well with the experimental measurements, which verifies the effectiveness of the presented identificationstrategy.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

Evolving asymmetric and anisotropic hardening of CP-Ti sheets under monotonic and reverse loading: Characterization and modeling

Commercially pure titanium (CP-Ti) sheets are promising to manufacture high-performance and lightweight components in many fields such as aerospace, marine, energy, electrics and healthcare. However, due to its low symmetric hexagonal close-packed (HCP) structure and complex thermal-mechanical processing history, CP-Ti sheets may exhibit significant asymmetry and anisotropy under monotonic and reverse loading. Therefore, the coupling effect of loading-path dependent asymmetric and anisotropic hardening behaviors of CP-Ti sheets need to be systemically characterized and accurately described under monotonic and reverse loading paths. In this study, firstly, the rheological tests were performed to systemically explore the evolving asymmetric and anisotropic hardening behavior of CP-Ti sheet under monotonic and reverse loading modes. With the help of anti-buckling support fixture and DIC system in tension and compression tests, the coupling effect of asymmetric and anisotropic hardening under monotonic and reverse loading of CP-Ti sheet was identified. Secondly, a loading-path dependent constitutive modeling framework was constructed in which the stress invariants-based model (SIM) integrated with distorted hardening (DH) under reverse loading (RL) conditions (SIM+DH+RL) were considered. Within the proposed modeling framework, a judging criterion of stress reversal for explicit solution method and an activation criterion of different reverse loading modes were introduced. Finally, the proposed SIM+DH+RL model was implemented, calibrated and further applied to simulate typical V-/U-bending of CP-Ti sheets. The results show that the proposed SIM+DH+RL model can significantly improve the prediction accuracy of V-/U-bending springback with the relative errors less than 7.8% and 2.1%, compared with 15.2% and 12% relative errors of Mises+IH, 19.5% and 7.3% relative errors of SIM+DH, 15.1% and 8.4% relative errors of Yoon2014+IH, 14.5% and 5.2% relative errors of CPB06+IH, and 17.3% and 11.5% relative errors of Hill48+IH. It is noted that for the thickness distributions after V-/U-bending springback, the above used models have similar prediction accuracies with the relative errors less than 1.8%.

VANADIUM ALLOYING IN S355 STRUCTURAL STEEL: EFFECT ON RESIDUAL AUSTENITE FORMATION IN WELDED JOINTS HEAT AFFECTED ZONE

The inter-critical heat affected zone (ICHAZ) appears to be one of the most brittle sections in the welding of high-strength micro-alloy steels (HSLA). Following multiple heating cycles in the temperature range between Ac1 and Ac3, the ICHAZ undergoes a strong loss of toughness and fatigue resistance, mainly caused by the formation of martensite-austenite constituent (MA). The presence of micro-alloying elements in HSLA steels induces variations in the formation of some microstructural constituents, more or less beneficial, which allow to improve the mechanical performance of a welded joint. The behavior in the inter-critical region of a S355 grade steel with 0.1wt% V addition is reported in this paper. Five double-pass welding thermal cycles were simulated using a dilatometer, with the maximum temperature of the secondary peak in the inter-critical area, in the range between 720 ° C and 790 ° C. The residual austenite dependence on inter-critical temperature is analyzed and related to the hardness behavior.

Synthesis, Microstructural Characterization, Mechanical, Fractographic and Wear Behavior of Micro B4C Particles Reinforced Al2618 Alloy Aerospace Composites

In the current studies an investigations were made to know the effect of 63 micron sized B4C particles addition on the mechanical and wear behavior of aerospace alloy Al2618 metal composites. Al2618 alloy with different weight percentages (2, 4, 6 and 8 wt. %) of 63 micron sized B4C particles reinforced composites were produced by stir cast process. These synthesized composites were tested for various mechanical properties like hardness, compression strength and tensile behavior along with density measurements. Further, microstructural characterization was carried by SEM/EDS and XRD analysis to know the micron sized particles distribution and phases. Wear behavior of Al2618 alloy with 2 to 8 wt. % of B4C composites were studied as per ASTM G99 standards with varying loads and sliding speeds. By adding 63 micron sized B4C particles hardness, compression and tensile strength of Al2618 alloy was enriched with slight decrease in elongation. Further, wear resistance of Al2618 alloy was enriched with the accumulation of B4C particles. As load and speed on the specimen increased, there was increase in wear of Al2618 alloy and its composites. Various tensile fracture surface morphology and worn surface behavior was observed by SEM analysis.

Reverse Magnetization Behavior Investigation of Mn-Al-C-(α-Fe) Nanocomposite Alloys with Different α-Fe Content Using First-Order Reversal Curves Analysis.

The reverse magnetization behavior for bulk composite alloys containing Mn-Al-C and α-Fe nanoparticles (NPs) has been investigated by hysteresis loops, recoil, and first-order reversal curves (FORC) analysis. The effect of adding different percentages of α-Fe (5, 10, 15, and 20 wt. %) on the magnetic properties and demagnetization behavior of Mn-Al-C nanostructured bulk magnets was investigated. The fabricated nanocomposites were characterized by XRD and VSM for structural analysis and magnetic behavior investigations, respectively. The demagnetization curve of the sample Mn-Al-C-5wt. % α-Fe showed a single hard magnetic behavior and showed the highest increase in remanence magnetization compared to the sample without α-Fe, and therefore this combination was selected as the optimal composition for FORC analysis. Magnetic properties for Mn-Al-C-5 wt. % α-Fe nanocomposite were obtained as Ms = 75 emu/g, Mr = 46 emu/g, Hc = 3.3 kOe, and (BH)max = 1.6 MGOe, indicating a much higher (BH)max than the sample with no α-Fe. FORC analysis was performed to identify exchange coupling for the Mn-Al-C-0.05α-Fe nanocomposite sample. The results of this analysis showed the presence of two soft and hard ferromagnetic components. Further, it showed that the reverse magnetization process in the composite sample containing 5 wt. % α-Fe is the domain rotation model.

The work hardening and softening behaviors of Mg–6Zn-1Gd-0.12Y alloy influenced by the VR/VD ratio

The effects of the VR/VD ratio (the volume fraction ratio of recrystallized grains and coarse deformed grains) on the work hardening and softening behaviors of Mg–6Zn-1Gd-0.12Y alloy were studied in detail by detecting the variation of dislocation density. The alloys with different VR/VD ratios were successfully fabricated by rolling and subsequently different annealing processes. It was shown that the higher VR/VD ratio closely related to the nucleation and growth of recrystallized grains could be obtained by an increase in annealing temperature. An increase in the VR/VD ratio from 0.16 to 24 reduced the work hardening rate in stage Ⅲ, while increased the work hardening rate in stage Ⅳ, which was closely related to the initial dislocation density and dislocation evolution. Low VR/VD ratio in the alloy, with high initial dislocation density, was identified to be beneficial for improving the work hardening rate in stage Ⅲ. And an increased VR/VD ratio could promote dislocation multiplication by stimulating the yield phenomenon due to the lack of initial dislocation density, and improve the work hardening rate in stage Ⅳ. With the VR/VD ratio increased, the softening behavior of the alloys increased in stage Ⅲ, and first decreased and then increased in stage Ⅳ. This was because the alloy with the lower dislocation density was easy to deform due to few obstacles, which accelerated the softening in stage Ⅲ, and improved dislocation density after yielding provided the strong driving force for the softening in stage Ⅳ. Meanwhile, the cycle stress relaxation tests further manifested that the stress drop values (Δσp) of the alloys were in close contact with the initial dislocation density and dislocation evolution influenced by the VR/VD ratio. As a result, when the VR/VD ratio was 1.6, the Mg–6Zn-1Gd-0.12Y alloy had excellent strength and toughness match owing to a dynamic balance between the work hardening rate and softening rate.

Bake hardening and uniaxial tensile behavior in a low carbon steel accompanying inhomogeneous plastic yielding

Bake hardening (BH) is a vital part of application-specific steel manufacturing. Previous studies on BH have focused on steels undergoing homogeneous yielding, which critically fails to observe and characterize various interesting phenomena that occur during inhomogeneous yielding. In this study, we investigated the BH behavior observed upon the application of inhomogeneous pre-strains. Two steels of identical composition that exhibited inhomogeneous plastic yielding during uniaxial tensile testing were prepared. One sample was composed of acicular ferrite while the other was composed of annealed polygonal ferrite. Inhomogeneous plastic yielding during uniaxial tensile testing is inevitably accompanied by the formation of a Lüders band (LB). When the LB propagated partially to the gauge section, no BH response (BHR) was observed in either steel during the re-loading of the pre-strained specimens after baking treatment (BT). However, when the LB propagated completely, BHR was exhibited by both steels. Digital image correlation analysis and macro-indentation testing confirmed that in the former cases, inhomogeneous hardening occurred due to inhomogeneous plastic yielding, whereas in the latter case, the inhomogeneous yielding was resolved, and hardening occurred uniformly throughout the gauge section. This influences not only BHR but also the overall uniaxial tensile properties such as tensile strength and total elongation. Nanoindentation and small-angle neutron scattering tests were performed on the pre-strained specimens before and after BT to determine the origin of the hardening effect. The results confirmed that nano-scale clusters/ε-precipitates can be formed at a low BT temperature if a Cottrell atmosphere is induced, thereby improving not only the BHR but also tensile strength.

Improvement of Mechanical Behavior of FSW Dissimilar Aluminum Alloys by Postweld Heat Treatments

AA6262 and AA5456 alloys are welded through friction stir weld (FSW) with process parameters of tool speed of 1200 rpm, welding speed of 25 mm/min, and tool angle of 3 degree. A cylindrical shape HSS-13 tool is used to perform the welding process To improve mechanical properties of tensile strength (TS), yield strength (YS), elongation%, hardness, and wear behavior, postweld heat treatment was conducted on the FSW sample at different temperatures from 300°C to 500°C. The influence of heat treatment (HT) changes the material characteristics. It is observed that the maximum TS (209 MPa) and YS (178 MPa) are identified when maintaining temperature 350°C on the FSW sample. The reduction in elongation of as-welded joints is entirely improved by HT, and the elongation percentage is almost increased to 5% when increasing temperature on the heat treatment process, and hardness test results exhibited that the increased hardness value (120Hv) is found at HT-300°C nugget zone distance of 0 to 5 mm range.

In-situ study of tensile deformation behaviour of medium Mn TWIP/TRIP steel using synchrotron radiation

This investigation proposes a pathway for generating optimum microstructure for a medium Mn containing twinning-induced plasticity/transformation-induced plasticity (TWIP/TRIP) steels. The steel contains a two-phase microstructure consisting of austenite and ferrite phase arranged in a lamellar fashion. The microstructure was developed following a specially designed thermo-mechanical processing schedule that involved quenching and partitioning. The feedback for the design of thermo-mechanical processing was obtained by carrying out in-situ deformation in high energy synchrotron radiation under tensile loading. Diffraction patterns were analysed for estimating the retained austenite phase fraction and other aspects of microstructural evolution. X-ray line profile analysis was performed to determine crystallite size, dislocation density, and twin density at individual stages of deformation. In the early stages, deformation occurs by dislocation slip in both phases, while in the later stages, deformation in the austenite phase occurs via twinning and martensitic transformation, and in the ferrite phase by dislocation slip. Strain hardening behaviour has been analysed and correlated with microstructural parameters.

Lattice dynamics and elastic properties of α-U at high-temperature and high-pressure by machine learning potential simulations

Studying the physical properties of materials under high pressure and temperature through experiments is difficult. Theoretical simulations can compensate for this deficiency. Currently, large-scale simulations using machine learning force fields are gaining popularity. As an important nuclear energy material, the evolution of the physical properties of uranium under extreme conditions is still unclear. Herein, we trained an accurate machine learning force field on α-U and predicted the lattice dynamics and elastic properties at high pressures and temperatures. The force field agrees well with the ab initio molecular dynamics (AIMD) and experimental results and it exhibits higher accuracy than classical potentials. Based on the high-temperature lattice dynamics study, we first present the temperature-pressure range in which the Kohn anomalous behavior of the Σ4 optical mode exists. Phonon spectral function analysis showed that the phonon anharmonicity of α-U is very weak. We predict that the single-crystal elastic constants C44, C55, C66, polycrystalline modulus (E, G), and polycrystalline sound velocity (CL, CS) have strong heating-induced softening. All the elastic moduli exhibited compression-induced hardening behavior. The Poisson's ratio shows that it is difficult to compress α-U at high pressures and temperatures. Moreover, we observed that the material becomes substantially more anisotropic at high pressures and temperatures. The accurate predictions of α-U demonstrate the reliability of the method. This versatile method facilitates the study of other complex metallic materials.

High-temperature wear properties of CrFeHfMnTiTaV septenary complex concentrated alloy film produced by magnetron sputtering

Entropy stabilized multicomponent alloys offer remarkable mechanical properties and thermal stability rendering these alloys for high-temperature protective films. A novel septenary CrMnFeHfTiTaV complex concentrated alloy (CCA) film was deposited using magnetron sputtering on 304 stainless steel (SS) and silicon substrates. The phase evolution, nano hardness, and tribological behavior of the film were investigated. The as-deposited CCA film displayed a stable amorphous phase up to 600 °C. The indentation hardness of the CCA film was 6.9 GPa compared to 3.3 GPa of the 304 SS substrate. The ball-on-disc wear tests showed that the coefficient of friction (COF) of 304 SS substrate increased from 0.40 at room temperature to 0.46 at 300 °C, whereas for the CCA film, it decreased from 0.82 to 0.44 due to the formation of a lubricating oxide layer. The COF of the 304 SS and the CCA film was similar at 500 °C, however, the wear rate on the CCA film was 7.9 × 10−5 mm3 N−1 m−1 and on the 304 SS was 158.6 × 10−5 mm3 N−1 m−1. The septenary CrMnFeHfTiTaV complex concentrated alloy films offered a robust technology to increase the surface properties of 304 SS and provide wear protection from oxide ceramics such as Al2O3 counter face from RT to 500 °C.

RETRACTED: Evaluation of pseudo-strain hardening behavior of hybrid fiber reinforced ultra-high performance concrete containing coarse aggregates by using micromechanical principles

In this study, pseudo-strain hardening (PSH) behavior of hybrid fiber reinforced ultra-high performance concrete containing coarse aggregates (UHPC-CA) and the synergistic effect of hybrid fibers were investigated. First, three types of fiber hybrid samples, namely, 2% short steel fiber (SSF2), 1.5% short steel fiber + 0.5% long steel fiber (SSF1.5 + LSF0.5) and 1.5% short steel fiber + 0.5% PE fiber (SSF1.5 + PE0.5), were designed and tested for their tensile properties. The results showed that the tensile strength and peak tensile strain of SSF1.5 + LSF0.5 were 19.9% and 183.3% higher than the corresponding values of SSF2, respectively. The tensile strength of SSF1.5 + PE0.5 was 3.6% lower than that of SSF2, but its ductility was 4.5 times higher than that of SSF2. Next, three-point bending tests on notched beams and single-crack tensile tests were conducted to evaluate the PSH behavior of hybrid fiber reinforced UHPC-CA by using micromechanical principles. The results showed that all groups met the strength and energy criteria with PSH index values of 5.86, 11.28, and 14.66 for SSF2, SSF1.5 + LSF0.5, and SSF1.5 + PE0.5, respectively. The higher the PSH index of the specimens, the greater the tensile ductility, which is consistent with the tensile test results. These results suggest that it is reasonable to evaluate the PSH behavior of hybrid fiber reinforced UHPC-CA by using micromechanical principles. Third, mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) analyses were performed to clarify the potential micromechanical properties of the hybrid fibers in improving the tensile properties of UHPC-CA. The MIP results showed that the total porosity was closely related to the initial cracking strength of the matrix; The smaller the total porosity, the higher the initial cracking strength of the matrix. The SEM results showed the characteristics of the PE fibers and the matrix. The bond strength between the PE fibers and the matrix was found to be high, leading to various damage patterns during the pull-out process of the PE fibers. Moreover, the combination of PE fibers and steel fibers showed a good synergistic effect, which explains the reason for the significant improvement in the ductility of the specimens when 1.5% steel fibers and 0.5% PE fibers were mixed.

Ultrathin ferrite nanosheets for room-temperature two-dimensional magnetic semiconductors

The discovery of magnetism in ultrathin crystals opens up opportunities to explore new physics and to develop next-generation spintronic devices. Nevertheless, two-dimensional magnetic semiconductors with Curie temperatures higher than room temperature have rarely been reported. Ferrites with strongly correlated d-orbital electrons may be alternative candidates offering two-dimensional high-temperature magnetic ordering. This prospect is, however, hindered by their inherent three-dimensional bonded nature. Here, we develop a confined-van der Waals epitaxial approach to synthesizing air-stable semiconducting cobalt ferrite nanosheets with thickness down to one unit cell using a facile chemical vapor deposition process. The hard magnetic behavior and magnetic domain evolution are demonstrated by means of vibrating sample magnetometry, magnetic force microscopy and magneto-optical Kerr effect measurements, which shows high Curie temperature above 390 K and strong dimensionality effect. The addition of room-temperature magnetic semiconductors to two-dimensional material family provides possibilities for numerous novel applications in computing, sensing and information storage.

Modeling of extra strengthening in gradient nanotwinned metals based on molecular dynamics

Gradient nanotwinned metals exhibit extra strengthening and work hardening behaviors, which have enormous potential for engineering applications. In this study, molecular dynamics method is performed for analyzing the effects of nanotwinned structure gradient on uniaxial tensile loading behaviors of gradient nanotwinned metals. Results show that the elasticity, dislocation stored ability and dislocation evolution of the nanotwinned lamellar are affected by the surrounding nanotwinned structure. Moreover, we established a quantitative phenomenological plastic flow stress model for gradient nanotwin metals based on physical connotation, and discussed the effects of nanotwinned thickness and nanotwinned structure gradient on the strength. Particularly, the back stress associated with the nanotwinned structure gradient and the contribution of geometrically necessary dislocations to statistically stored dislocations is included in our model. The tensile response the theoretical model descripted is in good agreement with the experimental results. We hold the opinion that the promotion effect of geometrically necessary dislocations to statistically stored dislocations will not be manifested until the nanotwinned structure gradient reaches a critical value. This research provides guidance for the structural design of gradient nanotwinned metals.

Plasticity and brittleness of the ordered βo phase in a TNM-TiAl alloy

In order to identify the reasons for the brittleness of a TNM-TiAl alloy (Ti51.05Al43.9Nb4Mo0.95B0.1 in at.%), the plastic deformation behaviour of the ordered βo phase is investigated. The corresponding powder was densified by Spark Plasma Sintering to produce a near lamellar microstructure made of γ/α2 lamellar colonies surrounded by γ and βo grains. Then, the room temperature tensile behaviour is studied by carrying out tensile tests and additional in-situ straining experiments in a transmission electron microscope (TEM). The TNM alloy exhibits a limited ductility, with the fracture surface of test specimens showing cleavage facets along lamellar interfaces. In addition, the βo grains contain nano-precipitates of the ωo phase and deform plastically by <111> superdislocations dissociated into two superpartial dislocations separated by an antiphase boundary. These dislocations glide in {011} planes and are observed to be localized into pile-ups, which is related to the ωo strengthening precipitation within the βo grains. This localised hardening behaviour leads to stress concentration in grain boundaries which is assumed to be responsible for delamination along lamellar interfaces in neighbouring lamellar colonies.

A general yield function with differential and anisotropic hardening for strength modelling under various stress states with non-associated flow rule

Sheet metal experiences various stress states during plastic deformation, including uniaxial compression, shear, uniaxial, plane strain and equibiaxial tension, but the existing yield functions cannot precisely model the differential strain hardening behaviour under different stress states. In this research, a stress invariant-based yield function is proposed to illustrate differential hardening by an analytical appraoch under distinct stress states (eg. from uniaxial compression to equibiaxial tension). The convex domain of the proposed function is computed by a simple geometry-inspired numerical convex analysis method. The parameters of the function are analytically computed by hardening behaviours under four different stress states from uniaxial compression to equibiaxial tension, such as uniaxial tension, equibiaxial tension, shear and plane strain tension. The proposed function is utilized to describe the plastic behaviour of AA7075 T6, a high strength steel QP1180, and a magnesium alloy AZ31 under the four different stress states from the onset of plastic deformation to fracture. Simulations with the proposed function are conducted to predict the load response of experiments in shear and notched tensile tests. The function is further extended into anisotropic hardening by interpolation method with the Barlat’91 linear transformation tensor. The result shows that the experimental responses are precisely predicted from the proposed yield function under various stress states in the entire range of plastic deformation. The application to BCC, FCC and HCP metals suggests that the proposed function is capable of precise modelling of differential hardening behaviours under four different stress states and strength differential effect and its evolution.

A thermodynamically-based constitutive theory for amorphous glassy polymers at finite deformations

In this work, a fully thermomechanical coupling constitutive theory is developed for amorphous glassy polymers to explain and predict their complex temperature- and rate-related nonlinear behavior during finite deformations. The foundation for the theory is the original kinematic and thermodynamic framework derived by Bouvard et al. (2013), in which internal state variables with clear physical significance are applied to describe the deformation mechanism of polymers. In contrast to the viewpoint of Bouvard et al. (2013), in the proposed model, we further divide the entanglements into two kinds of molecular microstructures, “permanent entanglements” and “dynamic entanglements”, and describe how their evolution during deformation is regarded as the internal mechanism for the material's macroscopic mechanical properties. Further, a series of new constitutive equations related to “dynamic entanglements” are proposed, which account for the strain softening caused by the dissociation of “dynamic entanglements”, reflect the influence of temperature on the dissociation rate of “dynamic entanglements” and include the effect of rate-dependent glass transition temperature (θg) on the microstructure. The equations related to “permanent entanglements” are also illustrated, which are improved based on the the work of Ames et al. (2009). The predictive capacity of the proposed thermomechanical coupling constitutive theory has been numerically realized by writing a user subroutine for finite element program. Taking polycarbonate (PC) as an example, the simulations are compared with experimental results for compression, shear, tension, and creep at different temperatures and strain rates. It is demonstrated that our proposed constitutive model with a more detailed physical meaning can well reproduce nonlinearity before yield, yield peak, strain softening, hardening and unloading behavior for amorphous glassy polymers under different stress states.