Fracture Characteristics Research Articles

Assessing potential factors leading to perioperative peri-implant fracture in femoral pertrochanteric fracture osteosynthesis using the proximal femoral nail antirotation 2: A retrospective study

BackgroundPerioperative peri-implant fractures (PPIFs) pose infrequent yet significant challenges in orthopedic surgery, particularly in the context of femoral pertrochanteric fractures (FPF) treated with proximal femoral nail antirotation 2 (PFNA-2) nails. PPIFs can lead to prolonged recovery and may necessitate re-osteosynthesis in severe cases. Despite the effectiveness of PFNA-2 in the management of FPFs, our understanding of PPIFs in this specific context remains limited. This study aimed to elucidate the factors contributing to PPIFs in patients with PFNA-2-treated FPF.MethodsIn this retrospective analysis spanning from 2019 to 2022, patients with FPF treated with PFNA-2 nails were examined. Demographic data, fracture characteristics, and radiological parameters were collected, along with details of the PPIF management strategies and rehabilitation protocols. Radiological assessments included femoral morphology measurements and reduction and fixation quality evaluation. The area under the curve (AUC) was analyzed in this specific group.ResultsAmong 157 patients, 3.2% experienced acute PPIFs managed conservatively with successful union without secondary surgical intervention. Younger age and increased femoral isthmus diameter (DI) emerged as significant predictors of PPIFs in the univariate regression analyses (P = 0.01). The AUCs for age (65.5 years) and DI (1.4 cm) were 0.78 and 0.79, respectively, indicating moderate accuracy.ConclusionsAlthough PFNA-2 nails are reliable in managing FPFs, the persistence of PPIFs emphasizes their complex causes. This study highlights that younger age and increased femoral DI are crucial factors for PPIF occurrence in patients with PFNA-2-treated FPF. Conservative treatment with delayed weight-bearing ambulation may be effective in treating these fractures.

Fracture characteristics of recycled aggregate concrete using work-of-fracture and size effect methods: the effect of water to cement ratio

Fracture characteristics of recycled aggregate concrete using work-of-fracture and size effect methods: the effect of water to cement ratio

Slip characteristics of planar and rough granite fractures under unloading normal force

Unloading processes are common in natural systems. Intense unloading activities can alter the frictional equilibrium of faults and induce their instabilities. Understanding the slip behavior of faults under stress unloading conditions is helpful in guiding engineering practices. We conducted a series of direct shear experiments under linear-unloading normal force conditions considering the influences of initial normal forces, initial shear forces, and normal unloading rates on planar and rough granite fractures. The experimental results showed that planar fracture exhibits sudden slip events during normal unloading, while rough fracture mostly displays stable sliding behavior. The planar fracture demonstrates an exponential increase in sliding distance and velocity at the end of each slip event. The rough fracture usually exhibits a quasi-static stage before rapid slip events. In addition, the accumulative sliding distance at the slip activation moment (at the first moment when sliding velocity is greater than 0.05 mm/s) for the planar fracture decreases with lower normal unloading rate, larger shear force and larger normal force, while its variation trend for rough fracture is opposite. These findings provide valuable insights into fault slip behavior under stress unloading, aiding in mitigating associated risks in engineering applications.

Fracture characteristics of human cortical bone influenced by the duration of in vitro glycation

Abstract Advanced glycation end products (AGEs) accumulate in various tissues, including bone, due to aging and conditions like diabetes mellitus. To investigate the effects of AGEs on bone material quality and biomechanical properties, an in vitro study utilized human tibia, sectioned into 90 beams, and randomly assigned to three mechanical test groups. Each test group included ribose (c=0.6 M) treatment at 7-, 14-, and 21-day, alongside control groups (n=5 per group). Fluorescent AGE (fAGE) and carboxymethyl-lysine (CML) levels were assessed through fluorometric analysis and mass spectrometry, while bone matrix composition was characterized using Fourier-transform infrared and Raman spectroscopy. Mechanical properties were determined through nanoindentation and three-point bending tests on non-notched and notched specimens. The results showed significant increases in fAGEs levels at 7-, 14-, and 21-day compared to controls (119%, 311%, 404%; p=0.008, p<0.0001, p<0.0001; respectively), CML levels also rose substantially compared to controls (383%, 503%, 647%, p<0.0001, p<0.0001, p<0.0001; respectively). Analysis of bone matrix composition showed greater sugars/Amide I ratio at 21-day glycation compared to controls, 7-day, and 14-day (p=0.001, 0.011, 0.006; respectively); and higher carbonate-to-phosphate ratios in the ribose treatment group compared to controls (p<0.05) in the interstitial bone area. Mechanical testing of notched specimens exhibited a higher yield force, pre-yield toughness, and growth toughness at 14-day glycation compared to controls and to both 7-day and 21-day glycation (p<0.05). Nanoindentation showed that the hardness was lower at 7-day glycation compared to the controls and 21-day glycation (p<0.05). In conclusion, the study found altered mechanical properties at 7 and 14 days of glycation, which then returned to control levels at 21 days, indicating a dynamic relationship between glycation duration and mechanical characteristics that deserves further exploration.

Pediatric Scaphoid Nonunions: Does Insurance Status Play a Role?

Objective: There are no studies that evaluate the effects that insurance or socioeconomic status may have on treatment and outcomes of scaphoid nonunions in children. We evaluated whether there is an association between insurance status and (1) time from injury to hand surgeon evaluation, (2) time from specialist evaluation to surgery, and (3) postoperative outcomes of scaphoid fracture nonunions in children. Methods: A chart review was performed for patients who underwent surgical treatment of scaphoid fracture nonunion from January 2015 and April 2021 at a large tertiary care pediatric hospital. Underinsured patients were defined as those with no medical insurance or Medicaid/state-funded insurance. Results: There were 21 privately insured patients and 17 patients who were underinsured. There was no difference in age, race, or fracture characteristics between the two groups. The mean time between injury and hand surgeon evaluation was 192 SD 195 days for the privately insured group compared with 155 SD 205 days for the underinsured group (P = 0.57). The mean time between specialist evaluation and surgical treatment was 35 SD 54 days for the privately insured group and 31 SD 31 days for the underinsured group (P = 0.82). Union was achieved in 80% of patients with private insurance compared with 88% of underinsured patients after primary surgery (P = 0.67). There was no difference detected in the proportion of patients who had residual pain (15% vs 19%), range of motion deficits (38% vs 40%), strength deficit (6% vs 7%), and return to activity (94% vs 93%) between privately insured and underinsured patients, respectively (P = 1.00). Conclusions: There was no difference in time from injury to specialist evaluation, time from evaluation to surgery, or postoperative outcomes based on insurance status for pediatric patients with scaphoid fracture nonunions. Although insurance status was not associated with access to care for pediatric scaphoid fracture nonunions at our institution, this information may not be generalizable to other populations, including patients who sustain primary scaphoid fractures and who have not yet developed nonunions. Level of Evidence: Level III—retrospective cohort study.

The Study and Application on Ductile Fracture Criterion of Dual Phase Steels During Forming

High-strength steel exhibits complex fracture behavior due to the interplay between shear and necking mechanisms during stamping and forming processes, posing challenges to achieving the dimensional accuracy and reliability demanded for automotive body panels. Existing prediction methods often fail to simultaneously account for both tensile and shear fracture characteristics, thereby limiting their predictive accuracy under diverse stress conditions. To address this limitation, we propose a ductile fracture criterion that integrates both tensile and shear mechanisms, calibrated using a single tensile–shear test to facilitate practical engineering applications. This study investigates the fracture characteristics of DP780 dual-phase steel through numerical analysis and tensile–shear experiments. The findings establish a relationship between stress triaxiality and ultimate fracture strain across varying stress states, represented by the B–W curve. Simulations reveal distinct stress triaxiality behaviors under different loading conditions: under uniaxial tensile loading, triaxiality ranges from 0.33 to 0.6, with fracture strain decreasing monotonically as triaxiality increases. Under shear loading, triaxiality ranges from 0 to 0.33, with fracture strain increasing monotonically as triaxiality rises. Additional bending simulations validate that this criterion, along with the B–W curve, reliably predicts the fracture behavior of DP780, offering an effective tool for predicting fracture in dual-phase steels during stamping and forming processes.

Experimental and numerical investigation on ductile fracture of Q235 cold-formed thin-walled steel

In order to simulate the full-range moment-rotation characteristic of steel storage rack beam-to-upright connections incorporating material fracture, this paper presents experimental and numerical investigations into the fracture behaviour of Q235 cold-formed thin-walled steel (CFTWS) flat and corner materials. A total of 43 specimens derived from Q235 CFTWS plates were tested. Two different thicknesses (1.8 mm and 3.25 mm), three varied bend angles (0°, 70° and 90°), and five types of specimens representing different stress states, were considered. The load-displacement curves and fracture characteristics of each specimen were derived from tests. The refined numerical models were established and validated by the test data. Based on experimental and numerical simulation results, four commonly used ductile fracture models for metal materials were calibrated and compared. The results show that the verified LMVGM fracture model is applicable to Q235 CFTWS flat and corner materials, and then compiled into a USDFLD subroutine in numerical simulation models to predict the flexural behaviour of storage rack beam-to-upright connections. The comparison between test and numerical simulation results illustrates that the established ductile fracture model for Q235 CFTWS materials can accurately simulate the fracture related failure modes of beam-to-upright connections in CFTWS storage racks.

The Lightweight Fracture Segmentation Algorithm for Logging Images Based on Fully 3D Attention Mechanism and Deformable Convolution

The challenge of fracture segmentation remains a significant obstacle in imaging logging interpretation within the current oil and gas exploration and development field. However, existing image segmentation algorithms still encounter issues related to accuracy, speed, and robustness, as well as a tendency to misdetect or overlook small fractures when applied to logging image fracture segmentation tasks. To address these challenges comprehensively, this paper proposes an end-to-end fracture segmentation algorithm named SWSDS-Net. This algorithm is built upon the UNet architecture and incorporates the SimAM with slicing (SWS) attention mechanism along with the deformable strip convolution (DSCN) module. The SWS introduces a fully 3D attention mechanism that effectively learns the weights of each neuron in the feature map, enabling better capture of fracture features while ensuring fair attention and enhancement for both large and small objects. Additionally, the deformable properties of DSCN allow for adaptive sampling based on fracture shapes, effectively tackling challenges posed by varying fracture shapes and enhancing segmentation robustness. Experimental results demonstrate that SWSDS-Net achieves optimal performance across all evaluation metrics in this task, delivering superior visual results in fracture segmentation while successfully overcoming limitations present in existing algorithms such as complex shapes, noise interference, and low-quality images. Moreover, serving as a lightweight network solution enables SWSDS-Net’s deployment on mobile devices at remote sites—an advancement that lays a solid foundation for interpreting logging data and promotes deep learning technology application within traditional industrial scenarios.

Fractures of the Hamate Bone: A Review of Clinical Presentation, Diagnosis and Management in the United Kingdom.

Injury to the hamate can result in significant functional impairment and a negative impact on quality of life. These injuries, in general, occur very infrequently, and in the setting of an increasingly ageing population and more patients presenting post falls, clinicians are at risk of either misdiagnosing or failing to diagnose patients who sustain hamate fractures. This review finds that hamate fractures can occur through acute trauma or chronic repetitive stress. These injuries are often missed resulting in a delay to management. Common presenting features of hamate fractures include ulnar-sided palmar tenderness and paraesthesia in the ulnar nerve distribution, loss of grip strength and pain on swinging a gripped object. In examination, the hamate "pull test" is a highly sensitive test for hamate fractures. CT scan of the carpal bones is shown to be the gold standard investigation for the diagnosis of such injuries. Initial management of hamate fractures in the United Kingdom is in line with the National Institute of Health and Care Excellence (NICE) guidelines that involves immobilisation with a suitable splint and sling for comfort, adequate analgesia, rest and elevation. Specific management of hamate fractures is divided into conservative and surgical options; however, this review identifies the need for further research into which form of management is superior.

Synchronously strengthening and plasticizing of unsaturated polyester resin based on styrene-maleic anhydride oligomer

To synchronously strength and plasticize unsaturated polyester resin (UPR), maleic anhydride were directly added in the unsaturated polyester resin solution and form the styrene-maleic anhydride oligomer (SMAO) without initiation. The creating SMAO cross link with UPR by curing reaction, and the prepared UPR resin exhibit higher tensile, elongation, bending strength and higher impact strength simultaneously, 0.45, 0.36, 0.76 and 0.12 times than UPR matrix, SMAO-UPR exhibits obvious plastic fracture characteristics; The DSC result indicates that the curing degree of SMAO-UPR is 96.55% which is 1.45% lower than that of UPR; The TG result indicates that MA and St mainly form an alternating copolymer below 90°C. The SEM and DMA result indicates that SMAO improves the morphology and structure which shows plastic deformation of UPR, and there is a certain interface effect between SMAO and UPR. Compared with the traditional method of large molecular weight SMA modified UPR, this method of reinforcing UPR is better for mechanical property, easy to operate, inexpensive, and highly applicable in industrial production.

Analysis of stress corrosion cracking failure of 316L stainless steel flow promoter string in the aggressive oilfield environment

This paper analyzes the failure mechanisms of stress corrosion cracking (SCC) in 316L stainless steel flow promoter strings in corrosive oilfield environments. Electrochemical tests and passive film analysis techniques were employed to elucidate the degradation behavior of the 316L stainless steel passive film. The fracture characteristics were analyzed using slow strain rate tensile tests, scanning electron microscopy, and electron backscatter diffraction techniques to clarify the SCC mechanisms. The results indicate that the SCC of 316L stainless steel is controlled by anodic dissolution due to passive film breakdown in the oilfield environment. The degradation of the passive film, induced by Cl- and CO2, promotes SCC in 316L stainless steel, with cracks propagating in a trans granular manner.

Experimental study on high-cycle fatigue performance of laser cladding additively manufactured 316L stainless steel

Laser cladding (LC) technology has garnered significant attention for its application in the repair of corrosion damage in steel structures. However, research on the high-cycle fatigue performance of LC materials remains limited. This study employed 316L stainless steel powder to produce LC specimens and conducted uniaxial tensiletensile high-cycle fatigue tests to explore various laser deposition directions and surface roughnesses. The resulting SN curves provide insights into the high-cycle fatigue behaviour of LC materials. Additionally, SEM images were utilized to analyse the fatigue failure fracture characteristics. The experimental results reveal that cladding materials deposited parallel to the loading direction exhibit superior high-cycle fatigue performance. Fatigue fractures in the specimens generally originate from laser fusion defects, which not only reduce the lifespan of the specimen but also influence the failure location. Fatigue failure assessments of the laser-cladded materials were conducted via equivalent life diagrams, which revealed a high degree of correlation with the actual failure conditions. Existing fatigue design curves for base materials can be applied to the high-cycle fatigue performance design of laser-cladded 316L stainless steel, demonstrating a performance that surpasses the average level of steel butt welds.

On revealing the mechanisms involved in brittle-to-ductile transition of fracture behaviors for γ-TiAl alloy under dynamic conditions

To understand the high-temperature behaviors of γ-TiAl is essential for its applications in aerospace industries. In this study, the high-temperature mechanical tests were carried out with strain rates ranging from 0.001 to 0.1 s−1 for the forged Ti-46Al-5Nb-1.8Cr-0.2Ta-0.1B alloy. The dynamic behaviors, fracture modes and microstructure evolution at elevated temperatures were analyzed to reveal the mechanisms involved in damage evolution. The results show that the brittleness of γ-TiAl is enhanced by strain rate hardening, and the brittle-to-ductile transition temperature (BDTT) increases with the increase of strain rates. The fracture morphology shows that the fracture characteristics transfer from the brittle fracture with mixed mode of intergranular and transgranular below and within the BDTT to the ductile fracture above BDTT. In addition, micro-cracks appear in fracture zones at the transitory stage, and cavities appear at the ductile stage, which is related to dynamic recrystallization (DRX). In this case, it is deduced that the brittle-to-ductile transition is induced by the competition between plastic deformation and crack propagation, and the results can be used to optimize the processing parameters towards high surface integrity when manufacturing γ-TiAl components.

Role of stable‐structural yarns and fabrics on the tensile and bending performance of carbon fiber resin composites

AbstractThe component yarns and fabrics effected the formability and stability of preforms, and finally determined the performance of corresponding composites. In this research, four typical fabric structures of carbon fiber resin composites (CFRC) were introduced to conduct the comparative investigation. The stability of component yarns in natural state and in fabrics have been discussed at mesoscopic scale, and the main methods to improve the structural stability of preforms were proposed. Composites with and without stable‐structural fibers and fabrics were manufactured by the modified curing process, and the yarn cross‐sections in specimens were analyzed. The tensile and bending performance of these composite specimens was comparatively conducted to discuss the influence of stable preforms on the elastic properties. The fracture mode and mechanism of specimens were illustrated in meso‐scale. The results depicted that yarns and fabrics with stable‐structural cross‐section could ensure a high fiber volume fraction, reducing the curvature of load‐bearing yarns, and effectively reduce the yarn curvature along bearing direction. The high interfacial bonding strength of composites with stable geometrical fabrics exhibited the excellent in‐plane mechanical properties, and presented the obvious brittle fracture characteristics when the fibers fully exert their load‐bearing capacity.Highlights Stable‐structural fibers result in the prominent performance of composites. Performance of composites with stable preforms show the low dispersion. Stable cross‐section of component yarns can enhance the stability of preforms. Low curvature yarns lead to brittle fracture characteristics of composites.

Predicting fracture strength of polarized GaN semiconductive ceramics under combined mechanical-current loading

Gallium nitride (GaN) piezoelectric semiconductor ceramics (PSCs) structures are often subjected to combined mechanical and electrical fields in engineering applications, leading to complex deformation and fracture challenges. This paper presents a fracture predictive model for PSCs under combined mechanical and electrical loading, developed using the boundary effect model rather than relying solely on data fitting. By introducing a current parameter that influences the characteristic crack length, the model effectively predicts the quasi-brittle fracture characteristics of GaN PSCs. Additionally, the model reveals how electric current affects the quasi-brittle fracture behavior of PSCs, providing crucial theoretical support for the reliable design of GaN intelligent semiconductor structures in complex environments.

Micro-Scale Fracture Characteristics of Emulsified Asphalt Cold Recycled Mixture Based on Discrete Element Method

Asphalt pavement often experiences structural failure due to repeated vehicle loading. The discrete element method (DEM) model was established based on the semicircle bending test (SCB) to investigate the fracture damage mechanism of emulsified asphalt cold recycled mixture (CRME) under loading. The micro-mechanical parameters of CRME were determined through a reliable validation process using the uniaxial compression static creep test. The microscopic fracture characteristics of CRME were investigated through the load-displacement curve, stress distribution, and force chain distribution. The fracture energy was used as the evaluation index to analyze the influence of prefabricated notch length and aggregate gradation on the fracture performance of CRME. The results indicate that the emulsified asphalt mortar-aggregate interface was the critical weak position of the mixture fracture; the failure of the tension chain was the main destructional form of the SCB test. The development of cracks affected the stress concentration phenomenon and stress concentration level of the mixture. Fine-grained mixture exhibited crack resistance. The number and length of cracks were affected by gradation. As the prefabricated notch length increased, the influence gradually diminished. The research results could provide theoretical and data support for the design of CRME.

Microstructure and Fracture Characteristics of HAZs of Ca- deoxidized Steel Plates with Different Ti/N Ratios After HHIW

Microstructure and Fracture Characteristics of HAZs of Ca- deoxidized Steel Plates with Different Ti/N Ratios After HHIW

Fracture Characteristics and Tensile Strength Prediction of Rock–Concrete Composite Discs Under Radial Compression

To investigate the fracture mechanism of rock–concrete (R–C) systems with an interface crack, Brazilian splitting tests were conducted, with a focus on understanding the influence of the interface crack angle on failure patterns, energy evolution, and RA/AF characteristics. The study addresses a critical issue in rock–concrete structures, particularly how crack propagation differs with varying crack angles, which has direct implications for structural integrity. The experimental results show that the failure paths in R–C disc specimens are highly dependent on the interface crack angle. For crack angles of 0°, 15°, 30°, and 45°, cracks initiate from the tips of the interface crack and propagate toward the loading ends. However, for angles of 60°, 75°, and 90°, crack initiation shifts away from the interface crack tips. The AE parameters RA (rise time/amplitude) and AF (average frequency) were used to characterize different failure patterns, while energy evolution analysis revealed that the highest percentage of energy consumption occurs at a crack angle of 45°, indicating intense microcrack activity. Moreover, a novel tensile strength prediction model, incorporating macro–micro damage interactions caused by both microcracks and macrocracks, was developed to explain the failure mechanisms in R–C specimens under radial compression. The model was validated through experimental results, demonstrating its potential for predicting failure behavior in R–C systems. This study offers insights into the fracture mechanics of R–C structures, advancing the understanding of their failure mechanisms and providing a reliable model for tensile strength prediction.

Influence of nano‐silica particles on fracture features of recycled aggregate concrete using boundary effect method: Experiments and prediction models

AbstractThe aim of this investigation is to assess the impact of using nano‐silica (Na) at varying weight percentages of 0%, 1.5%, 3%, 4.5%, and 6% as partial cement substitute on fracture parameters of recycled aggregate concrete (RAC). A servo‐controlled testing system was employed to carry out three‐point flexure tests on 90 notched beams. Boundary effect method was used in order to interpret the fracture features. The results illustrate that adding Na increases the size‐independent fracture energy, fracture toughness and initial fracture energy of RAC by 29%, 32%, and 24% compared to that without Na, respectively. The maximum values of these parameters occur at 4.5% Na. The reference crack length () decreases from 6% to 22% by adding 1.5% to 6% Na. This shows that the RAC gets more brittle by the addition of Na. Moreover, the RAC behavior moves towards linear elastic fracture mechanics criteria by adding Na. Finally, according to the mechanical properties and test variables, multivariable models were suggested for prediction of the fracture parameters of the RAC containing Na. The models predictions were compared with experimental findings of the previous research.

Effect of Process Parameters on the Mechanical Properties of Simultaneous Double-Sided Friction Stir Welding Joints

Currently, conventional single-sided friction stir welding is primarily suitable for joining thin plate aluminum alloys, and its application to thick plates is still challenging in terms of welding efficiency and joint mechanical properties. Simultaneous double-sided friction stir welding (SDS-FSW) is a high-efficiency joining technique specifically developed for welding thick plates. However, there is little research on the influence of SDS-FSW process parameters on the joint mechanical properties. In this study, a 12 mm thick AA6061-T6 aluminum alloy and dual robot welding equipment are used to conduct SDS-FSW experiments exploring the influence of rotational speed ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega$$\\end{document} and welding speed v on the mechanical properties and microstructure. The results show that when the welding parameters are ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega$$\\end{document} = 800 r/min and v = 60–80 mm/min, smooth and defect-free thick plate aluminum alloy SDS-FSW joints can be obtained, and the macroscopic morphology of the joints is distributed in a “dumbbell” shape. The grain size in the weld nugget zone increases with increasing welding heat input. The microhardness distribution in the joint displays a “W” shape, and the hardness value of the weld nugget zone can reach 67% to 86% of that of the base metal (BM). The junction between the thermo-mechanically affected zone and the heat affected zone is the weakest region of the joint, with the lowest hardness being approximately 51% of that of the BM. When the welding parameters are ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega$$\\end{document} = 800 r/min and v = 140 mm/min, the SDS-FSW joint has the highest tensile strength, reaching 78.43% of the BM strength and exhibiting ductile fracture characteristics. This research indicates that acceptable weld strength in thick aluminum alloys can be achieved via the SDS-FSW joining mechanism, highlighting its significant potential for industrial applications.