Compressive Component Research Articles

Tensile theoretical modeling and auxetic behavior analyzing of negative Poisson’s ratio yarn

In this paper, the tensile models of the negative Poisson’s ratio yarn with incompressible component yarn and compressible component yarn are constructed. The theoretical Poisson’s ratio curves exhibit the same trend as the experiment. Compared with the theoretical model of incompressible component yarns, a 14% reduction was found in the maximum negative Poisson’s ratio value in the compressible component yarns model. Additionally, the modified theoretical model was established to improve further the accuracy of the model. Both the variation trend and Poisson’s ratio value of the theoretical curves are highly consistent with the experimental results, and the average difference rate of the maximum Poisson’s ratio value is below 10%, which proves the effectiveness of the corrected theoretical model in predicting the auxetic behavior. Our theoretical model not only considers the initial helical path of the wrap yarn could not be completely horizontally straightened when it is just subject to an axial tensile force but also takes the influence of component yarn sectional shape changes into account. The as-constructed theoretical model is more realistic and can guide the design of negative Poisson’s ratio yarn and optimize the theoretical modeling method.

Wrist-ankle acupuncture for primary dysmenorrhea: a randomized controlled trial evaluating the efficacy of an analgesic strap.

Drawing on the principles of wrist-ankle acupuncture (WAA), our research team has developed a portable device for WAA point compression, termed the acupressure wrist-ankle strap (AWA). The current study aims to evaluate the efficacy of the AWA in alleviating pain associated with primary dysmenorrhea. A single-blind, randomized clinical trial was conducted from April 1, 2019, to December 31, 2019. 78 participants with primary dysmenorrhea were recruited from Shanghai University of Traditional Chinese Medicine. All participants were treated on the first day of menstruation for 30 min. Participants in the AWA group used the AWA, the internal side of which is equipped with a tip compression component, while participants in the non-acupressure wrist-ankle acupuncture(NAWA)group used the NAWA, with the inside tip pressing parts removed. The main outcome was the difference in visual analogue scale (VAS) score between baseline and 30 minutes after randomization. A total of 78 participants aged 18 to 30 years were included in the intention-to-treat analyses. The VAS scores (mean [standard deviation]) in the AWA group were significantly lower than those in the NAWA group at each time point of intervention (5 minutes: 95% CI, [-1.27 to -0.68], p < 0.001; 10 minutes: 95% CI, [-2.34 to -1.51], p < 0.001; 30 minutes: 95% CI, [-3.74 to -2.72], p < 0.001). In the AWA group, 16 participants reported "obvious relief" of dysmenorrhea pain while 23 did not; the average onset time of analgesia they reported were (21.50 ± 3.65) min, while no subjects in NAWA group reported obvious pain relief. The pain threshold (mean [standard deviation]) at SP9 of both sides in AWA group decreased significantly after intervention that in NAWA group (Left: 95% CI, [-5.02 to -1.81], p < 0.001; Right: 95% CI, [-7.67 to -4.24], p < 0.001). There was no significant change in the temperature at CV4 in either group (95% CI, [-0.63 to -0.66], p = 0.970). This trial substantiates our hypothesis that the AWA provides immediate analgesic effects. The AWA represents an effective and safe non-invasive physical therapy option, which patients can self-administer to alleviate abdominal pain.

Design of acceleration control schedule for adaptive cycle engine based on direct simulation model

To design the optimum acceleration control schedule for the Adaptive Cycle Engine (ACE) in the full flight envelope, this paper establishes a direct simulation model of the ACE transient state. In this model, geometric parameters are used to replace the component state parameters. The corresponding relationship between geometric parameters and component state parameters is determined by sensitivity analysis. The geometric variables are controlled when the geometric adjustment speed exceeds the limit, and at the same time the corresponding component state parameters are iterated. The gradient optimization algorism is used to optimize the ground acceleration process of ACE, and the control schedule in terms of operating point of compression components and corrected acceleration rate is used as the full-envelope acceleration control schedule based on the similarity principle. The acceleration control schedules of the triple-bypass mode and the double-bypass mode are designed in this paper. The acceleration processes under various flight conditions are simulated using the acceleration control schedules. Compared with the acceleration process with the linear geometric adjustment schedule, the acceleration performance of ACE is improved by the acceleration control schedule, with the impulse of the acceleration process of the triple-bypass mode being increased by 8.7%–12.3% and the impulse of the double-bypass mode acceleration process being increased by 11.8%–14.1%.

Special all‐round fillet weld for anchor rods of base‐plate T‐stub connections

SummaryThe eccentricity between connected steel parts and the anchor rods in base‐plate T‐stub connections makes base plates the weaker components in tension and compression. Additionally, the oversized holes in base plates lead to irregular placement of anchor rods, resulting in an unsymmetrical shear behavior. Thus, this paper aims to develop a special all‐round fillet weld to connect the anchor rods beneath the base plate concentrically to the steel part, removing the base plate from the load‐transferring chain. Accordingly, design criteria were first developed based on Eurocode's directional method considering all the potential failure modes. Next, results were validated by conducting experimental work. The digital image correlation technique (DIC) was also used to capture the strain distribution developed over the tested specimen till failure. Consequently, numerical analysis was carried out to investigate the fracture strength and the fracture angle and compare the special fillet weld with its equivalent standard one, which has the same weld volume. The results indicated that the proposed design criteria produced safe strength prediction for the developed special all‐round fillet weld. Furthermore, the results revealed that using a special all‐round fillet weld instead of the equivalent standard one can increase the strength by about 8% and improve the ductility of the weld. However, it decreases the stiffness of the weld by about 21%. The fracture surface occurred at from the face of the anchor rod, which produced a higher strength than the predicted tensile strength calculated according to the theoretical throat plane.

Effect of tie column on the progressive collapse performance of infilled reinforced concrete frames

In practice, reinforced concrete (RC) infilled frames having longer span are provided with tie columns to improve structural integrity but previous work ignored tie columns in studying the effect of masonry infills on progressive collapse resistance of RC frames. Therefore, aim of this study is to explore the effect of tie columns on the progressive collapse resistance of RC infilled frames under column removal scenarios. The high-fidelity-based finite element model of RC infilled frames were first developed and validated with published experimental results. The validated model was then further evolved to an RC infilled frame having tie columns to evaluate the influence of tie columns on the load transfer mechanism and the resistance of the RC infilled frame against progressive collapse. Thereafter, the numerical model was further utilized to study the effects of the pertinent parameters, including the number of stories, the span length of the frame and the longitudinal reinforcement ratio of the tie columns. Finally, equivalent strut model was suggested for macro-modeling of RC infilled frames having tie columns in engineering practice. The results showed that incorporating tie columns makes truss mechanism more fully mobilized in masonry infill walls and the inclined angles of primary struts in each sub-panel of the infill wall are increased, improving the vertical components of diagonal compression in resisting the gravity load. Consequently, introducing tie columns at middle span of infill wall panels helped to increase the initial stiffness (about 19%), peak resistance (about 26%) and post-peak resistance of RC infilled frame under a middle column removal scenario. Such beneficial effect of tie columns becomes more significant for infilled frames with larger spans, and the longitudinal reinforcement ratio of tie columns should be ≤ 0.24%.

Cosmic-Ray Drag and Damping of Compressive Turbulence

While it is well known that cosmic rays (CRs) can gain energy from turbulence via second-order Fermi acceleration, how this energy transfer affects the turbulent cascade remains largely unexplored. Here, we show that damping and steepening of the compressive turbulent power spectrum are expected once the damping time becomes comparable to the turbulent cascade time. Magnetohydrodynamic simulations of stirred compressive turbulence in a gas-CR fluid with diffusive CR transport show clear imprints of CR-induced damping, saturating at , where is the turbulent energy input rate. In that case, almost all of the energy in large-scale motions is absorbed by CRs and does not cascade down to grid scale. Through a Hodge–Helmholtz decomposition, we confirm that purely compressive forcing can generate significant solenoidal motions, and we find preferential CR damping of the compressive component in simulations with diffusion and streaming, rendering small-scale turbulence largely solenoidal, with implications for thermal instability and proposed resonant scattering of E ≳ 300 GeV CRs by fast modes. When CR transport is streaming dominated, CRs also damp large-scale motions, with kinetic energy reduced by up to 1 order of magnitude in realistic E CR ∼ E g scenarios, but turbulence (with a reduced amplitude) still cascades down to small scales with the same power spectrum. Such large-scale damping implies that turbulent velocities obtained from the observed velocity dispersion may significantly underestimate turbulent forcing rates, i.e., .

Compressible spectral mixture kernels with sparse dependency structures for Gaussian processes

Spectral mixture (SM) kernels comprise a powerful class of generalized kernels for Gaussian processes (GPs) to describe complex patterns. This paper introduces model compression and time- and phase (TP) modulated dependency structures to the original (SM) kernel for improved generalization of GPs. Specifically, by adopting Bienaymé’s identity, we generalize the dependency structure through cross-covariance between the SM components. Then, we propose a novel SM kernel with a dependency structure (SMD) by using cross-convolution between the SM components. Furthermore, we ameliorate the expressiveness of the dependency structure by parameterizing it with time and phase delays. The dependency structure has clear interpretations in terms of spectral density, covariance behavior, and sampling path. To enrich the SMD with effective hyperparameter initialization, compressible SM kernel components, and sparse dependency structures, we introduce a novel structure adaptation (SA) algorithm in the end. A thorough comparative analysis of the SMD on both synthetic and real-life applications corroborates its efficacy.

Performance of Novel U-Connector in CFS Truss-to-Column Bolted Connection under Axial Force

This paper presents an experimental and numerical investigation of the tensile and compressive behaviour of a novel U-connector in the cold-formed steel (CFS) truss-to-column connection. Tensile tests were performed on 12 specimens representing the tension chords of the trusses in the connection. The results were used to validate a finite element model. The validated model was then subjected to both compressive and tensile loads, which revealed low stiffness in both the compressive and tensile components of the proposed connection. An optimisation of the geometry by using one long nut instead of two nuts was carried out to improve the behaviour and stiffness of the connection. The optimised results were compared with both experimental and numerical data, and conclusions were drawn regarding the effectiveness of the components in the proposed connection. The use of long-nut optimisation in the tension and compression components of the proposed connection shows a significant increase in load-bearing capacity, which makes it very promising for future applications in CFS truss-to-column connections. However, further validation through experimental testing is required to confirm the effectiveness and reliability of the connection in full-scale structures.

DESIGN OF WEARABLE TENSEGRITY STRUCTURES FOCUSING ON THE TENSION PROPAGATION FUNCTION THROUGHOUT THE BODY

AbstractHumans are able to perform skilful movements by coordinating muscles throughout the body. It has been revealed that not only neural mechanisms but also direct and dynamic interactions between body parts contribute to muscular coordination. Tensegrity, accurately biotensegrity, can be considered to the basic mechanism for the interactions. Tensegrity structures are composed of tensile and compressive components, and are lighter and more flexible than existing rigid structures. The authors investigated designing wearable tensegrity structures for extending human motor ability, especially assisting in carrying heavy objects. Based on Flemons' spine model, we devised a columnar tensegrity structure that can be expanded to the size of the whole body, and connected each of four columns to the front and back of the body on right and left side. The wearable tensegrity structures can deform flexibly due to tension distribution when external force is applied, and follow the human motions in twisting trunk and walking. Experimental results in carrying heavy objects showed that some muscle activities around hip and knee tended to decrease by using the structures when those joints extended.

Comparison of CT-FFR to invasively measured FFR adenosine and FFR dobutamine in patients with an anomalous aortic origin of a right coronary artery

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FNSNF - Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung. Introduction Anomalous aortic origin of a right coronary artery (AAORCA) is a rare congenital anomaly. Malignant AAORCA with an interarterial course between the great arteries inherit an anticipated higher risk for myocardial ischemia. Anatomical high-risk features are beside the interarterial course the slit-like ostium (SLO), elliptic vessel shape (EVS), proximal narrowing (PN), acute take-off angle (ATOA) and an intramural course (IM) inside the aortic wall. The complex anatomy lead to both a fixed and further dynamic component of anomalous vessel compression. The suggested gold-standard for the assessment of combination (i.e. fixed and dynamic component) is invasively measured fractional flow reserve (FFR) during dobutamine and volume challenge, whereas FFR under adenosine may only cover the fixed components. A possible non-invasive alternative for FFR assessment is novel CT-FFR method, which can calculate FFR from coronary computed tomography angiogram (CCTA) images using computational fluid dynamics (CFD). Purpose CT-FFR may be used as a non-invasive alternative to invasive FFR measurements. Our aim was to compare CT-FFR to invasively measured FFRadenosine and FFRdobutamine in patients with AAORCA. Methods Consecutive patients enrolled in the NARCO trial (i.e. Noninvasive anatomical assessment for ruling out hemodynamically relevant coronary artery anomalies – A comparison of coronary-CT to invasive coronary angiography), with AAORCA undergoing CCTA and invasively measured ischemia assessment were included. All patients underwent CCTA for quantification of anatomical high-risk features and analysis of CT-FFR, invasive coronary angiography using FFR with adenosine (140μg/kg/min) and secondly with dobutamine and volume challenge (40 μg/kg/min + saline: 1.5–3 l+ atropine: 1 mg). Comparison between different methods was performed. Results In total, 29 consecutive patients with an AAORCA with an interarterial course (56 ± 13 years old), 22 (76%) male patients who underwent both CCTA and invasive coronary angiography were included. SLO was present in 18 (62%), PN in 5 (17%), EVS in 29 (100%) and an ATOA in 29 (100%) patients. An IM was present in 28 (97%) with a mean length of 11 ± 4 mm. While there was no difference between CT-FFR and FFRadenosine (p = 0.656), the mean invasive measured FFRdobutamine (0.85 ± 0.11), was significantly lower than FFRadenosine (0.88 ± 0.10, p = 0.002) and trend towards lower values than CT-FFR (0.89 ± 0.06, p = 0.063). Conclusion In patients with AAORCA, CT-FFR shows no difference with FFRadenosine, but they both overestimate FFR compared to FFRdobutamine gold-standard. Hence, there is a need for CCTA derived CFD FFR models, including dynamic components and mimicking FFR under dobutamine stress.

Study on the water ingestion performance of compressor with inlet particle separator

Abstract For an aero turbo-shaft engine, rain water enters the intake protection device and the morphology of water droplets after hitting the wall will affect the internal flow of the compressor. In this paper, Sommerfeld number was used to determine the shape of water droplets after they hit the wall. The flow field and characteristics of the compressor with inlet particle separator under different water ingestion conditions were studied with considering the impact of water film and droplets splashing near the wall. The results show that the entry of water droplets deteriorates the internal flow field of the compression component, and the water film affects the flow state of the airflow near the wall. Compared to the effect of the splashing factor, the viscous resistance effect of water film near the wall on the airflow and boundary layer can cause a significant reduction in the characteristics and stability of the compressor.

Activated twinning variant determination in cold-rolled 316L stainless steel by effective Schmid factor analysis

A method is proposed to determine accurately the activated twinning variant during the cold-rolling of 316L stainless steel parts produced by L-PBF (Laser Powder Bed Fusion) from EBSD datas. The twinning variant selection is carried out by Schmid factor (SF) computations, using an effective Schmid factor for cold-rolling specifically. Schmid factor was proven to be a relevant parameter to predict the experimentally activated twinning variant. Additionally, cold-rolling deformation is shown to be composed by a strong compression component, along with a minor traction component. The effective Schmid factor is then modified accordingly to ensure a better prediction of twinned grains. Moreover, twinning Schmid factor analyses in traction and compression provide valuable information on the twinning activation regarding textured materials such as L-PBF 316L steel.

Comprehensive SNN Compression Using ADMM Optimization and Activity Regularization.

As well known, the huge memory and compute costs of both artificial neural networks (ANNs) and spiking neural networks (SNNs) greatly hinder their deployment on edge devices with high efficiency. Model compression has been proposed as a promising technique to improve the running efficiency via parameter and operation reduction, whereas this technique is mainly practiced in ANNs rather than SNNs. It is interesting to answer how much an SNN model can be compressed without compromising its functionality, where two challenges should be addressed: 1) the accuracy of SNNs is usually sensitive to model compression, which requires an accurate compression methodology and 2) the computation of SNNs is event-driven rather than static, which produces an extra compression dimension on dynamic spikes. To this end, we realize a comprehensive SNN compression through three steps. First, we formulate the connection pruning and weight quantization as a constrained optimization problem. Second, we combine spatiotemporal backpropagation (STBP) and alternating direction method of multipliers (ADMMs) to solve the problem with minimum accuracy loss. Third, we further propose activity regularization to reduce the spike events for fewer active operations. These methods can be applied in either a single way for moderate compression or a joint way for aggressive compression. We define several quantitative metrics to evaluate the compression performance for SNNs. Our methodology is validated in pattern recognition tasks over MNIST, N-MNIST, CIFAR10, and CIFAR100 datasets, where extensive comparisons, analyses, and insights are provided. To the best of our knowledge, this is the first work that studies SNN compression in a comprehensive manner by exploiting all compressible components and achieves better results.

Identification of QTL, QTL-by-environment interactions, and their candidate genes for resistance HG Type 0 and HG Type 1.2.3.5.7 in soybean using 3VmrMLM.

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is an important disease affecting soybean yield in the world. Potential SCN-related QTLs and QTL-by-environment interactions (QEIs) have been used in SCN-resistant breeding. In this study, a compressed variance component mixed model, 3VmrMLM, in genome-wide association studies was used to detect QTLs and QEIs for resistance to SCN HG Type 0 and HG Type 1.2.3.5.7 in 156 different soybean cultivars materials. The results showed that 53 QTLs were detected in single environment analysis; 36 QTLs and 9 QEIs were detected in multi-environment analysis. Based on the statistical screening of the obtained QTLs, we obtained 10 novel QTLs and one QEI which were different from the previous studies. Based on previous studies, we identified 101 known genes around the significant/suggested QTLs and QEIs. Furthermore, used the transcriptome data of SCN-resistant (Dongnong L-10) and SCN-susceptible (Suinong 14) cultivars, 10 candidate genes related to SCN resistance were identified and verified by Quantitative real time polymerase chain reaction (qRT-PCR) analysis. Haplotype difference analysis showed that Glyma.03G005600 was associated with SCN HG Type 0 and HG Type 1.2.3.5.7 resistance and had a haplotype beneficial to multi-SCN-race resistance. These results provide a new idea for accelerating SCN disease resistance breeding.

Stress waves in laser-material interaction: From atomistic understanding to nanoscale characterization

During pulsed laser-assisted manufacturing, the extremely high-temperature gradient in space will lead to very high-stress waves that play a critical role in structuring. Both shear and normal stress waves emerge in space. This work provides a review and perspective based on our past work spanning theoretical analysis, 1D molecular dynamics (MD) modeling, 3D MD modeling, and experimental characterization. Discussions are given on the non-Fourier effect during ultrafast laser-material interaction, stress-induced structural defects in recrystallization, and ablation confinement by ambient gas and nanotip during nanotip-assisted near-field nanomanufacturing. The presence of stress waves in space could cause permanent and temporary damages, and these damages are more caused by the shear stresses than the normal ones where the compressive component usually is much stronger than the tensile part. Due to the fact of very fast stress waves propagation and slow cooling and solidification, it is very challenging to conduct MD modeling of the entire domain even using stage-of-the-art parallel computation. Hybrid modeling that combines MD and macroscale modelings provides a better choice to tackle this problem. Time-resolved ultrafast temperature and stress characterization are still highly needed to provide deep physics understanding of laser-material interaction toward process control and optimization.

Оценка сдвиговой прочности горных пород по трещинам на основе результатов испытаний образцов сферическими инденторами

Experimental data on the relationship of the residual shear strength of rocks in closed cracks with the functional characteristics of intact rocks – the tensile and compressive components of adhesion, the roughness of the crack surfaces, and the level of normal stresses are presented. A unified integrated approach determines the shear strength of intact and destroyed rocks, the residual shear strength of closed rough cracks has been developed. The approach provides for the selection of stress intervals corresponding to different types of fracture, for each of which a strength criterion is proposed, expressed in terms of functional characteristics of intact rock. An express method for estimating the residual shear strength of rocks by cracks with a rough surface has been developed, in which an improved method of loading samples with spherical indentors is used as a basic test method. The express method implements the transition from the data of mechanical tests of samples with spherical indentors to the shear strength indicators for cracks in the rock mass, taking into account the level of normal stresses and the roughness of the crack surfaces measured in field conditions. In this case the roughness scale developed by Barton is used. The express method is informative and available in the fieldwork.&#x0D;

Impact of Dynamic Change of Meandering of Parallel Artery to the Idiopathic Tarsal Tunnel Syndrome.

In idiopathic tarsal tunnel syndrome (TTS), walking seems to make symptoms worse. The findings imply that an ankle movement dynamic component may have an impact on the etiology of idiopathic TTS. We describe how the ankle movement affects the nerve compression caused by the surround tissue, particularly the posterior tibial artery. We enrolled 8 cases (15 sides) that had TTS surgery after tarsal tunnel (TT) MRI preoperatively. Dorsiflexion and plantar flexion were the two separate ankle positions used for the T2* fat suppression 3D and MR Angiography of TT. Based on these findings, we looked at how the two different ankle positions affected the posterior tibial artery's ability to compress the nerve. Additionally, we assessed the posterior tibial artery's distorted angle. We divided the region around the TT into four sections: proximal and distal to the TT and proximal half and distal half to the TT. Major compression cause was posterior tibial artery. Most severe compression point was proximal half in the TT in all cases without one case. In each scenario, the nerve compression worsens by the plantar flexion. The angle of the twisted angle of the posterior tibial artery was significantly worsened by the plantar flexion. In idiopathic TTS, deformation of posterior tibial artery was the primary compression component. Nerve compression was exacerbated by the plantar flexion, and it was attributable with the change of the distorted angle of the posterior tibial artery. This could be a contributing factor of the deteriorating etiology by walking in idiopathic TTS.

Estimation of crustal strain in Kashmir Himalayan region of north India using continuous GPS measurements

Global positioning system (GPS) measurements of crustal deformation provide insight into the crustal plate velocity and strain rate variation in the actively deforming Earth's crust. GPS measurements in the Kashmir Himalaya indicate that most of the crustal motion between the Indian Plate and southern China is accommodated along the Himalayan arc, resulting in the accumulation of crustal strain and locking of the Main Himalayan Thrust (MHT). Here, we present geodetically estimated spatial and temporal crustal strain rates in the Kashmir Himalaya from GPS measurements to understand the nature of crustal deformation. We processed and analysed GPS data from 21 sites across Kashmir Himalaya along with several IGS sites. We find that the average deformation rate of the GPS sites in Kashmir Himalaya with reference to the Indian Plate range between 2.8 and 15.5 ± 1 mm/year. The GPS results illustrate that the strain rate field is dominated by a compression component with its rate as 7.2 × 10−8 strain/year and the maximum shear strain, γmax, of 1.9 × 10−7 strain/year. The earthquake focal mechanisms suggest that earthquake activity in the Kashmir Himalaya is predominantly manifested in the form of thrust motion. The maximum principal shear strain value reflects that the Kashmir Himalaya is under NE–SW compressional regime. The spatial distribution of crustal strain indicates that the region north‐east of Kashmir Valley is accumulating maximum strain, resulting in the stress build‐up and could be the region of a future large earthquake.

Study of the Behavior of Self-Sensing Concrete under the Influence of Different Mechanical Loads: A Review

Self-sensing concrete is an intelligent application of scientific knowledge for practical purposes and new concrete structures, which can feel the damage, stress and strain in the body of concrete. It has been widely used because of its possibility of getting efficient cost solution for controlling the structural sustainability of concrete structures, which indicate, that it is very impressive during the design life of the facilities. This review contains universal behavior and global information about different conditions of loading for self-sensing concrete. Also, the definitions and applications of intrinsic and non-intrinsic self-sensing concretes are mentioned. Moreover, a major confirmation is stated on the application of scientific knowledge for practical purposes and new concrete structures. The characteristics of self-sensing concrete provide an ability to reveal small cracks before they begin to become significant. During unchanging compression, firstly, the values of electrical resistivity decrease through an increase in load, subsequently become stable and then increased suddenly. While, during impact loading, the electrical resistivity decreases suddenly, but it regresses then to 0 after loading. However under tensile stress, the electrical resistivity increases as the tensile stress increases. Nevertheless, since the flexural is a component of compression and tension, the comparison between sensitivity for compression part is much smaller than in tension part.

Phase-field viscoelastic fracture modeling of polymer composites using strain tensor spectral decomposition

The mechanical behaviors of polymer composites exhibit strong time-dependent nonlinearities, and the tensile and compressive strengths can be vastly different. Such a strength differential effect poses a great challenge in fracture modeling using existing phase-field models. To address this problem, this study develops a new viscoelastic fracture phase-field model, in which the strain tensor spectral decomposition is proposed to decompose the elastic energy of the equilibrium and non-equilibrium branches into tensile and compressive components. The non-negativity of elastic energy and the thermodynamic consistency are theoretically verified. Various case studies, spanning from material uniaxial tension–compression and compression under isostatic pressure to fracture processes of realistic structural components, are used to validate the proposed method. Results of the proposed method are compared with those of existing methods and the actual testing data of polymer composites to demonstrate the effectiveness of the method. It is shown that the proposed method can accurately model not only the strong strength differential effect but also the isostatic pressure dependence of viscoelastic materials. Furthermore, the proposed method offers a more precise prediction of the fracture path and can deal with the loading rate effect.