Fracture Threshold Research Articles

Stretched to the Limit: Comparing Polytetrafluoroethylene-Covered Endovascular Stents Through Serial Dilations

BackgroundCovered stents are used during congenital cardiac interventions to treat stenotic or injured vessels or to exclude unwanted vascular connections. The ability to postdilate a stented vessel to keep pace with somatic growth is critical in children. In this study, we aimed to compare in vitro performance of 2 brands of covered stents during serial dilations to demonstrate the threshold for stent fracture and polytetrafluoroethylene tear and define recoil and foreshortening characteristics. MethodsiCast and VBX stents of various sizes were measured before and after expansion and through serial dilations. Dilations were performed at 2-mm increments until stent fracture, polytetrafluoroethylene tear, and “napkin-ring” formation, to a maximum of 22-mm diameter. ResultsThe 5- and 6-mm VBX stents fractured during dilation with 10-mm balloon; the 7-mm VBX stents fractured on the 14-mm balloon; and the largest VBX stents fractured on the 20- or 22-mm balloons. iCast stents experienced partial fracture during dilation with the 14- or 16-mm balloons and complete fracture past dilation with 16-mm balloons. VBX stents recoiled less at nominal diameters. Both stents had similar foreshortening at nominal diameters, although VBX stents had more significant foreshortening with postdilation. ConclusionsAll iCast stents experienced partial fracture with dilation between 14- and 16-mm diameter and had unpredictable fracturing patterns. VBX stents showed a more predictable fracture pattern and had less recoil with nominal inflation but more foreshortening with postdilation. These findings may add clinical benefit and empower physicians to make optimal decisions regarding future planning of interventions in children with congenital heart disease.

Influence of water environment on paint removal and the selection criteria of laser parameters

Laser paint removal in a water environment does not diffuse ablation pollution products into air. Characteristics of water, such as high specific heat and heat flux, generate different effects of the laser paint removal than in an air environment. In this study, the effects of air and water environments on the mechanism and effect of laser paint removal are analyzed and compared experimentally and theoretically. In air, thermodynamic ablation causes removal of paint, whereas in water, stress coupled with plasma shock waves cause tear and splash removal of paint layers after fracture and damage. Fracture and pressure thresholds of the paint and substrate, respectively, indicate the optimum energy density range for laser paint removal in water, providing a reference for engineering applications.

Adjustable multifocus laser separation scheme for thick glass with flexibly controllable thermal stress distribution

As a high-quality thick glass separation method, multifocus technology has proven its superiority. For a certain thickness of glass, there must be an optimal multifocus distance. But, the positions of the foci cannot be adjusted flexibly in current multifocus schemes without changing the energy proportions; the influence of thermal stress distribution on the quality of thick glass separation has not been systematically studied. An adjustable multifocus laser scheme has been proposed in this paper and proved by optical design, ray tracing, and experiment. First, finite element simulations have been performed to analyze the thermal stress distribution inside 20 mm glass. The simulation results show that thermal tensile stress exceeds the fracture threshold only at the upper and lower sides of the glass but not in the middle; the maximum thermal tensile stress reduces inside the glass when the symmetrical focal distance increases. Then, a series of separation experiments of 20, 22, and 25 mm thick soda lime glass have been carried out, which have adjusted foci positions to control the thermal stress distribution. The experimental results show that the deviation length decreases with an increase of the foci distances, and the optimal symmetrical foci distances reduce as the glass thickness increases.

Computational prediction of head-ground impact kinematics in e-scooter falls

E-scooters are the fastest growing mode of micro-mobility with important environmental benefits. However, there are serious concerns about injuries caused by e-scooter accidents. Falls due to poor road surface conditions are a common cause of injury in e-scooter riders, and head injuries are one of the most common and concerning injuries in e-scooter falls. However, the head-ground impact biomechanics in e-scooter falls and its relationship with e-scooter speed and design, road surface conditions and wearing helmets remain poorly understood. To address some of these key questions, we predicted the head-ground impact force and velocity of e-scooter riders in different falls caused by potholes. We used multi-body dynamics approach to model a commercially available e-scooter and simulate 180 falls using human body models. We modelled different pothole sizes to test whether the pothole width and depth influences the onset of falls and head-ground impact velocity and force. We also tested whether the e-scooter travelling speed has an influence on the head-ground impact velocity and force. The simulations were carried out with three human body models to ensure that the results of the study are inclusive of a wide range of rider sizes. For our 10 in. diameter e-scooter wheels, we found a sudden increase in the occurrence of falls when the pothole depth was increased from 3 cm (no falls) to 6 cm (41 falls out of 60 cases). When the falls occurred, we found a head-ground impact force of 13.2 ± 3.4kN, which is larger than skull fracture thresholds. The head-ground impact speed was 6.3 ± 1.4 m/s, which is the same as the impact speed prescribed in bicycle helmet standards. All e-scooter falls resulted in oblique head impacts, with an impact angle of 65 ± 10° (measured from the ground). Decreasing the e-scooter speed reduced the head impact speed. For instance, reducing the e-scooter speed from 30 km/h to 20 km/h led to a 14% reduction in the mean impact speed and 12% reduction in the mean impact force, as predicted by the models. The models also showed that the median male riders were sustaining higher head-ground impact force and speed compared with the small female and large male riders. The findings of this study can assist authorities and e-scooter hiring companies to take more informed actions about road surface conditions and speed limits. These results can also help define representative impact test conditions for assessing the performance of helmets used by e-scooter riders in order to reduce head and brain injuries in e-scooter falls.

Transverse low-velocity impact performance of BFRP bars after exposure to the saline-alkaline environment

The saline environment is one of the most severe exposure conditions for infrastructure due to its corrosive nature. Fiber reinforcement polymer (FRP) bars are being considered as a replacement for steel rebars to prevent corrosion. However, the effects of saline environments and alkaline cementitious conditions on the impact performance of FRP bars are not well known. Therefore, this study aims at examining the low-velocity impact performance of basalt FRP (BFRP) bars after exposure to the saline-alkaline environment for 24, 48, and 72 days and elevated temperatures (25, 40, and 55 °C). The maximum load-bearing capacity, deformation capacity, and energy absorption capacity of the deteriorated BFRP bars are measured. Environmental scanning electron microscope (ESEM) and Fourier transform infrared spectroscopy (FTIR) were used to study the deterioration mechanism further. It was revealed that both the fracture threshold and the bending stiffness of BFRP bars generally decrease with the elevated exposure temperature and duration. The findings also suggest that deterioration of BFRP bars in a natural saline-alkaline environment is less severe than the simulated saline-alkaline solution. This study provides some insights to promote the application of FRP composites in coastal and marine structures in a saline-alkaline environment with low-velocity impact loads.

Models for the behavior of boron carbide in extreme dynamic environments

AbstractWe describe models for the behavior of hot‐pressed boron carbide that is subjected to extreme dynamic environments such as ballistic impact. We first identify the deformation and failure mechanisms that are observed in boron carbide under such conditions, and then review physics‐based models for each of these mechanisms and the integration of these models into a single physics‐based continuum model for the material. Atomistic modeling relates the composition and stoichiometry to the amorphization threshold, while mesoscale modeling relates the processing‐induced defect distribution to the fracture threshold. The models demonstrate that the relative importance of amorphization and fracture are strongly dependent on the geometry and impact conditions, with the volume fraction of amorphized material being unlikely to be significant until very high velocities (~3 km/s) are reached for geometries such as ball impact on plates. These connections to the physics thus provide guidelines for the design of improved boron carbide materials for impact applications.

Intervention thresholds to identify postmenopausal women with high fracture risk: A single center study based on the Philippines FRAX model

ObjectivesThis study is designed to estimate appropriate intervention thresholds for the Philippines Fracture Risk Assessment Tool (FRAX) model to identify postmenopausal women with high fracture risk. MethodsAge dependent intervention thresholds were calculated for a woman of body mass index 25 kg/m2 aged 50–80 years with a previous fragility fracture without other clinical risk factors. Fixed thresholds were developed using a database of 1546 postmenopausal women who underwent dual-energy X-ray absorptiometry for clinical reasons. Major and hip fracture risks were estimated using clinical risk factors with and without bone mineral density (BMD) input. Women were categorized to high risk and low risk groups according to the age dependent thresholds. The best cut-points were determined considering the optimum sensitivity and specificity using receiver operating characteristic analysis. ResultsThe age dependent intervention thresholds of major fracture risk ranged from 2.8 to 6.9% while hip fracture risk ranged from 0.4 to 3.0% between 50 and 80 years of age. Major fracture threshold of 3.75% and hip fracture threshold of 1.25% were the best fixed thresholds observed and non-inclusion BMD in the fracture risk estimations did not change the values. As a hybrid method, 3% major fracture and 1% hip fracture risks for those < 70 years old and age-dependent thresholds for those aged 70 years and above can be recommended. ConclusionsThe intervention thresholds estimated in the current study can be applied to identify Filipino postmenopausal women with a high fracture risk. Clinicians should decide on the type of thresholds most appropriate.

FRAX-based intervention thresholds for Pakistan.

The fracture risk assessment algorithm FRAX® has been recently calibrated for Pakistan, but guidance is needed on how to apply fracture probabilities to clinical practice. The age-specific 10-year probabilities of a major osteoporotic fracture were calculated in women with average BMI to determine fracture probabilities at two potential intervention thresholds. The first comprised the age-specific fracture probabilities associated with a femoral neck T-score of - 2.5. The second approach determined age-specific fracture probabilities that were equivalent to a woman with a prior fragility fracture, without bone mineral density (BMD). The parsimonious use of BMD was additionally explored by the computation of upper and lower assessment thresholds for BMD testing. When a BMD T-score ≤ - 2.5 was used as an intervention threshold, FRAX probabilities in women aged 50years were approximately two-fold higher than in women of the same age but with no risk factors and average BMD. The relative increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80years or more, a T-score of - 2.5 was actually protective. The 10-year probability of a major osteoporotic fracture by age, equivalent to women with a previous fracture, rose with age from 2.1% at the age of 40years to 17%, at the age of 90years, and identified women at increased risk at all ages. Intervention thresholds based on BMD alone do not effectively target women at high fracture risk, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a 'fracture threshold' target women at high fracture risk.

Toughening induced by the formation of facets in mode I+III brittle fracture: Experiments versus a two-scale Cohesive Zone model

When subjected to some anti-plane shear mode III loading, segmentation of the crack front frequently occurs during propagation: even if the crack is initially planar, propagation produces facets/segments rotated toward the shear free direction. Here, we examine, both experimentally and theoretically, the effect of this microstructure on the effective macroscale brittle fracture toughness. Experiments performed on PMMA beams reveal that the critical load leading to abrupt rupture increases with mode III to mode I ratio. This apparent macroscopic toughening is usually taken into account by invoking a specific mode III toughness in addition to the mode I one. By applying thoroughfully a micro/macroscale Cohesive Zone (CZ) model that we have recently developed, we demonstrate that an additional material constant is useless here since this toughness increase can be attributed mainly to the presence of the facets at the microscale, whose geometry can be anticipated to depend on the classical mode I material constants. More precisely, two related physical mechanisms are generated due to the formation of a disconnected crack front: (i) changes in fractured surface area in comparison to a straight propagation, and (ii) crack shielding caused by the facets that reduce the effective crack opening. While the first effect is obvious to quantify, we show that the second plays an essential role but is more complex to take into account: it depends on the solution of the three-dimensional elasticity problem in presence of the facets, that is considered in the CZ model. We illustrate on the experiments how to use this approach in practice to determine the critical fracture threshold.

Investigation of Delamination-Induced Performance Decay at the Cathode/LLZO Interface

The growing interest in solid-state batteries has resulted in increased focus on the issue of delamination at the cathode/solid-state electrolyte (SSE) interface. The extent of delamination, and its impact on impedance rise and capacity fade, is determined by a number of material properties, including cathode molar volume change and state-of-charge dependence, mechanical properties of the cathode and SSE, SSE grain boundary microstructure, fracture threshold of the interface, and interfacial exchange current density. The goal of this paper is to develop multiscale mathematical models to link these material properties to performance and provide guidance on possible approaches to minimize delamination, impedance rise, and capacity fade. We examine two cathodes, namely, LiNi0.8Mn0.1Co0.1O2 with a positive molar volume change and LiCoO2 with a negative molar volume change against a Li7La3Zr2O12 (LLZO) SSE. Density functional theory (DFT) is used to determine fundamental material properties at the interface, while mesoscale models are used to link these properties to macroscopic performance. Model results suggest that SSEs with smaller grains and low Young’s modulus and cathodes with low molar volume changes provide opportunities for minimizing delamination.

Enhancement of Magnetic and Tensile Mechanical Performances in Fe-Based Metallic Microwires Induced by Trace Ni-Doping.

Herein, the effect of Ni-doping amount on microstructure, magnetic and mechanical properties of Fe-based metallic microwires was systematically investigated further to reveal the influence mechanism of Ni-doping on the microstructure and properties of metallic microwires. Experimental results indicate that the rotated-dipping Fe-based microwires structure is an amorphous and nanocrystalline biphasic structure; the wire surface is smooth, uniform and continuous, without obvious macro- and micro-defects that have favorable thermal stability; and moreover, the degree of wire structure order increases with an increase in Ni-doping amount. Meanwhile, FeSiBNi2 microwires possess the better softly magnetic properties than the other wires with different Ni-doping, and their main magnetic performance indexes of Ms, Mr, Hc and μm are 174.06 emu/g, 10.82 emu/g, 33.08 Oe and 0.43, respectively. Appropriate Ni-doping amount can effectively improve the tensile strength of Fe-based microwires, and the tensile strength of FeSiBNi3 microwires is the largest of all, reaching 2518 MPa. Weibull statistical analysis also indicates that the fracture reliability of FeSiBNi2 microwires is much better and its fracture threshold value σu is 1488 MPa. However, Fe-based microwires on macroscopic exhibit the brittle fracture feature, and the angle of sideview fracture θ decreases as Ni-doping amount increases, which also reveals the certain plasticity due to a certain amount of nanocrystalline in the microwires structure, also including a huge amount of shear bands in the sideview fracture and a few molten drops in the cross-section fracture. Therefore, Ni-doped Fe-based metallic microwires can be used as the functional integrated materials in practical engineering application as for their unique magnetic and mechanical performances.

Effect of MTA versus CEM apical plugs on fracture resistance of endodontically treated simulated immature teeth restored with cast metal posts: an in-vitro study

BackgroundEndodontically treated immature teeth which are restored with cast metal posts are of the most susceptible teeth to fracture. An apical plug is usually used as root end filling in order to seal the wide apical foramen. The current study was performed to evaluate the effect of different apical plug materials (MTA and Calcium enriched mixture cement) at varied thicknesses on fracture resistance of teeth restored with cast metal posts.MethodsA total of 40 extracted intact single-rooted human mandibular premolars (removed for orthodontic reasons) were used in the study. The coronal part of each tooth was removed and root canal preparation was performed. A size 4 Gates Glidden drill was used to enlarge the canal and was passed through the apical foramen in order to simulate an immature apex. Samples were randomly divided into 5 groups (n = 8) according to apical plug (control group: No plug, group MTA5: 5 mm MTA plug, group CEM5: 5 mm CEM plug, group MTA3: 3 mm MTA plug, group CEM3: 3 mm CEM plug). Post-space preparations were performed and cast metal post-and-cores were fabricated and cemented. Fracture resistance was assessed using a universal testing machine. Fracture thresholds were recorded and data were analyzed using One-way ANOVA and Dunnett’s T3 tests with significance level at P value < 0.05.ResultsThe analysis showed a significant difference of fracture resistance between groups (P value < 0.05). The mean fracture resistance of samples in control group was significantly lower than MTA5 (P value = 0.003). There was no significant difference between other groups (P value > 0.05).ConclusionsWithin the limits of this study, the evidence indicated that placement of a 5 mm MTA apical plug increased the fracture resistance in simulated immature teeth which are restored with cast metal posts, compared to control group (gutta-percha and sealer). While the results were not as promising for a 3 mm MTA apical plug or either 3 or 5 mm CEM apical plug.

Relationship between spinal structural damage on radiography and bone fragility on CT in ankylosing spondylitis patients

To evaluate whether the risk of bone fragility on computed tomography (CT) (scanographic bone attenuation coefficient of the first lumbar vertebra (SBAC-L1)) is associated with the severity of spine structural involvement (mSASSS) in patients with ankylosing spondylitis (AS). This retrospective study included AS patients, followed from 2009 to 2017, who fulfilled the New York criteria and who underwent thoraco-abdomino-pelvic CT and radiography (spine, pelvis). The structural involvement was retained for mSASSS ≥ 2. The SBAC-L1 was measured in Hounsfield units (HU). A SBAC-L1 ≤ 145 HU was used to define patients at risk of vertebral fracture (VF). A total of 73 AS patients were included (mean age: 60.3 (± 10.7) years, 8 women (11%), mean disease duration: 24.6 years (± 13.9)). Sixty patients (82.2%) had a mSASSS ≥ 2 (mean score 20.7 (± 21.2)). The mean SBAC-L1 was 141.1 HU (± 45), 138.1 HU (± 44.8) and 154.8 HU (± 44.9) in the total, mSASSS ≥ 2 and mSASSS < 2 populations, respectively. Patients with bone bridges had lower SBAC-L1 than mSASSS ≥ 2 patients without ankylosis (p = 0.02) and more often SBAC-L1 ≤ 145 HU (73% vs 41.9%, p = 0.006). A SBAC-L1 ≤ 145 HU was not associated with structural spine involvement, but patients with bone bridges had significantly decreased SBAC-L1 and an increased probability of being under the fracture threshold.

Coupled crack propagation and dendrite growth in solid electrolyte of all-solid-state battery

Lithium metal all-solid-state batteries (ASSBs) are promising candidates for future lithium batteries thanks to their high safety performance and energy density. However, Li dendrite growth and interfacial failure are the two fatal issues deteriorating the cyclability that hinders the wide commercialization of ASSBs. To further understand the underlying mechanisms, a coupled electrochemical-mechanical phase-field model for grain crack propagation and lithium dendrite growth is proposed from the energy conservation perspective in this study. We discover that longer defect with sharp edge and angle ( θ ≥ 45 ° ) causes more severe crack propagation and leads to larger dendrite growth area due to the increased strain energy density. We observe that the initial defect within grain plays an irrelevant role in the dendrite growth within the grain boundary. Stacking pressure greater than 10 MPa significantly speeds up crack propagation as well as dendrite growth due to the nontrivial mechanical driving force. Mechanical stress-induced strain-energy would contribute to more than 15% of the total dendrite growth once the stacking pressure exceeds 20 MPa, while it is trivial if the stacking pressure is below 10 MPa. Large enough fracture threshold strain can prevent the crack propagation. Results provide a fundamental tool for the design and evaluation of ASSB safety and cyclability from a more comprehensive perspective and clear the barrier for the development of next-generation ASSBs. • A coupled model for crack propagation and Li dendrite growth is proposed. • Longer defect with sharp edge and angle promotes crack propagation and dendrite growth. • Stacking pressure above 10 MPa greatly assists crack propagation and dendrite growth. • Strain-energy contributes more than 17% of the dendrite growth if the stacking pressure is above 20 MPa.

Head/skull injury potential of empty 0.5-l beer glass bottles vs. 0.33-l Coke bottles

The medical and biomechanical assessment of injuries from blows to the head is a common task in forensic medicine. In the context of a criminal justice process, the injury potential of different striking weapons is important. The article at hand compares the injury potential of assaults with a 0.5-l beer bottle and a 0.33-l Coke bottle, both made of glass. The research team hit 30 used empty 0.5-l beer bottles and 20 used empty 0.33-l Coke bottles manually on an aluminum dummy skull set on a force measuring plate, using acrylic and pork rind as a scalp surrogate. There was no significant difference in fracture threshold and energy transfer between the examined beer and Coke bottles. Both glass bottles are able to cause fractures to the facial bones while cranial bone fractures are primarily not to be expected. Blows with a 0.5-l beer bottle or with a 0.33-l Coke bottle to the head can transfer up to 1.255 N and thus are able to cause severe blunt as well as sharp trauma injuries.

Achieving exceptionally tensile properties and damage tolerance of 5083 aluminum alloy by friction stir processing assisted by ultrasonic and liquid nitrogen field

The emergence of gradient structures has realized the possibility of improving the strength and plasticity of metals simultaneously. This study analyses the effects of introducing ultrasonic and liquid nitrogen during conventional stirring and friction treatment. The results show that the mechanical properties and damage tolerance of 5083 aluminum (Al) alloy can be substantially improved by the simultaneous application of two external fields (called UNFSP specimens). The average yield strength and tensile strength of the UNFSP specimens were 58.2% and 27.5% higher than those of the as-received 5083 Al alloy without reduction in its elongation, respectively. In addition, compared with the as-received 5083 Al alloy, the threshold of fatigue crack propagation and the fracture threshold of the UNFSP specimens also increased by 62.9% and 25.7%, respectively. The main reason for these improvements was the contribution of the gradient structure with high density of geometrically necessary dislocations, thicker fine grains layer, and seriously refined Fe/Mn-containing particles.

Rupture Risk Assessment of Cervical Spinal Manipulations on Carotid Atherosclerotic Plaque by a 3D Fluid-Structure Interaction Model.

Method The FSI model, based on MRI data of an atherosclerosis patient, was used to simulate the deformations of the plaque and lumen during the process of two kinds of typical cSMT (the high-speed, low-amplitude spinal manipulation and the cervical rotatory manipulation). The biomechanical parameters were recorded, such as the highest wall shear stress (WSS), the maximum plaque wall stress (PWS), the wall tensile stress (Von mises stress, VWTS), and the strain. Result The max_WSS was 33.77 kPa in the most extensive deformation. The highest WSS region on the plaque surface was also the highest PWS region. The max_PWS in a 12% stretch was 55.11 kPa, which was lower than the rupture threshold. The max_VWTS of the cap in 12% stretch which approached the fracture stress level was 116.75 kPa. Moreover, the vessel's max_VWTS values in 10% and 12% stretch were 554.21 and 855.19 kPa. They were higher than the fracture threshold, which might cause media fracture. Meanwhile, the 7% stretched strain was 0.29, closed to the smallest experimental green strains at rupture. Conclusion The carotid arteries' higher stretch generated the higher stress level of the plaque. Cervical rotatory manipulation might cause plaque at a high risk of rupture in deformation after 12% stretch and more. Lower deformation of the plaque and artery caused by the high-speed, low-amplitude spinal manipulation might be safer.

Assessment of the force attenuation capability of 3D printed hip protector in simulated sideways fall

An innovative 3D printed hip protector has been designed and tested to decrease the possibility of hip fracture in a sideways fall to a hard surface. The main design purpose was to create custom fit hip protector, reduce the manufacturing period and make the protector comfortable to wear. This work compares the new energy shunting 3D printed hip protector design with an existing energy absorbing hip protector. A drop tower mechanical test rig was designed and developed to simulate a sideways fall with sufficient impact energy to fracture an unprotected greater trochanter (GT). The test rig incorporates the actual geometry of a femur made from steel and uses a foam to simulate trochanteric soft tissue over the greater trochanter. Similar impact energy was used for the testing of each hip protector. The weight of the striker mass was maintained, and the height was adjusted to obtain an impact energy of 21–43J to produce femoral neck force of 3–9 kN. Results illustrate that the 3D hip protector compares favorably in attenuating impact force capable of causing hip fracture to a value below the fracture threshold of 3.472 kN. The influence of the 3D hip protector on peak transmitted forces to the vulnerable site of the greater trochanter is shown to be positive. It is anticipated that future protectors can be 3D printed after optimizations to end the bundling of same hip protector for different body geometry.

Investigation of femur fracture potential in common pediatric falls using finite element analysis

A finite element (FE) model of an 11-month-old child’s femur was developed to evaluate fracture risk in short-distance feet-first falls and bed falls. Pediatric material properties were applied to the FE model. Femur loading was derived from previously conducted fall experiments using a child surrogate where fall conditions (e.g., fall height, impact surface) were varied. Fracture thresholds based on principal stress and strain were used to examine potential for fracture. Peak stress/strain were significantly greater for feet-first falls from greater heights and onto harder impact surfaces. Feet-first falls exceeded some, but not all fracture thresholds. Bed falls did not exceed any fracture thresholds.

Polyprotein Cross-linked Hydrogels with High Stretchability, Fracture Toughness and Low Hysteresis

It is challenging to realize both high fracture toughness and low hysteresis perfectly in synthetic systems, which restricts the use of stretchable hydrogels in load-bearing applications. Recently, by imbedding the folded polyprotein cross-linker in a percolating random coiled network, Cao et al. demonstrated a highly stretchable hydrogel, which shows low hysteresis(<5%) but achieves high fracture toughness(ca. 900 J/m2). Moreover, the hydrogel shows outstanding anti-fatigue properties with a fatigue fracture threshold of 126 J/m2. The unique network structure breaks the hysteresis-toughness correlation that is usually reported in stretchable and tough hydrogels. This work has been published in the Nature Communications and can be reached at https://doi.org/10.1038/s41467-020-17877-z .