Uniaxial Tests Research Articles

Mechanical and Microstructural Behavior of Cemented Paste Backfill Under Cyclic Loading

Understanding the mechanical and physical behavior of aged CPB under cyclic loading is a significant area of research. Many parameters such as cementation (hydration) and the microstructure, which dictate the arrangement of particles and permeability, affect the mechanical features of cemented paste backfill (CPB). The impact of a wide range of external energy sources within the mining environment, such as cyclic loading resulting from long-term blasting, can significantly alter the applied stresses on the backfill mass. This paper aims to delve into this crucial area of research. A series of uniaxial cyclic tests were conducted on CPB, utilizing samples made from tailing materials sourced from a copper mine in South Australia. Different loading levels were applied at various curing times. All samples exhibited cyclic loading hardening behavior for cyclic loading levels between 80% and 93% of monotonic unconfined compressive strength (UCS), and a cyclic loading damage behavior was observed for 96% of UCS loading level for both 14- and 28-day curing periods. To further investigate these findings, scanning electron microscope analysis as well as sonic velocity tests were conducted for capturing microstructural changes in the samples before and after tests. These findings can be used to indicate a safe firing distance to a filled mass.

Study on the Mechanical Characteristics and Degradation Response of Unloading Rocks Surrounding Tunnels in Cold Regions

The excavation of the rock mass at the tunnel entrance in regions characterized by high altitudes and elevated stress levels results in the direct exposure of the surrounding rock to atmospheric conditions. This surrounding rock is subjected to the compounded effects of excavation-induced unloading damage and freeze–thaw erosion, which contribute to the degradation of its mechanical properties. Such deterioration has a negative impact on production and construction operations. Following tunnel excavation, the lateral stress exerted by the surrounding rock at the tunnel face is reduced, leading to a predominance of uniaxial compressive stress. As a result, the failure mode and mechanical behavior of the rock exhibit characteristics similar to those observed in uniaxial loading tests conducted in controlled laboratory environments. This study conducts laboratory-based uniaxial loading and unloading tests, as well as freeze–thaw tests, to examine the strength, deformation characteristics, and fracture attributes of unloading sandstone subjected to freeze–thaw erosion. A damage deterioration model for unloading sandstone under uniaxial conditions is developed, and the patterns of damage response are further analyzed through the identification of compaction points and the definition of damage response points. The results indicate that (1) as the degree of freeze–thaw erosion increases, the failure threshold of the sandstone significantly decreases, with the residual rock fragments on the fracture surface transitioning from hard and sharp to soft and sandy; (2) freeze–thaw erosion has a pronounced negative impact on the cohesion of the sandstone, while the reduction in the internal friction angle is relatively moderate; and (3) the strain induced by damage following three, six, and nine freeze–thaw cycles exhibits a gradual decline and appears to reach a state of stabilization when compared to conditions without freeze–thaw exposure. Investigating the mechanical properties and deterioration mechanisms of the rock in this specific context is crucial for establishing a theoretical foundation to assess the stability of the tunnel’s surrounding rock and determine the necessary support measures.

Validation of Muscle Ultrasound Speckle Tracking and the Effect of Nordic Hamstring Exercise on Biceps Femoris Displacement.

This study aimed to validate the ultrasound speckle tracking (UST) algorithm, determine the optimal probe location by comparing normalized cross-correlation (NCC) values of muscle displacement at two locations (proximal vs. middle) of the biceps femoris long head (BFlh) using the UST, and investigate the effects of Nordic hamstring curl exercise (NHE) training on BFlh displacement. UST efficacy was verified with ex vivo uniaxial testing of porcine leg muscles. Ten participants (mean age 23.4 y) were recruited for comparison of NCC values between the proximal and middle BFlh during maximal knee flexor eccentric contraction using an ultrasound device and isokinetic dynamometer. Using the above devices, electromyography and shear wave elastography, the effects of an 8-wk NHE program on the morphomechanical profiles, displacement and activation of the middle BFlh and eccentric torque of the knee flexor were investigated in 20 males (mean age 23.5 y). The validity of UST was confirmed by comparing UST and ex vivo test results (r = 0.99). The NCC values of the middle BFlh were greater than those of the proximal BFlh. The caudal-direction displacements of the BFlh in the dominant leg were reduced after the NHE training (from 3.98 ± 3.84 to 1.50 ± 4.17 mm, p < 0.05). The magnitude of reduction was associated with improved eccentric strength of the knee flexor muscle in the dominant leg (r = 0.63). UST is a validated tool for measuring muscle displacement. NHE training decreased caudal-direction muscle displacement in the BFlh and increased eccentric strength.

Numerical testing method and mechanical property evaluation of large particle size asphalt mixture.

The large particle size asphalt mixture with nominal maximum aggregate size 53 mm(LSAM-50) has good technical and economic performance and will become an effective technical way to build a full-thick long-life asphalt pavement with Chinese characteristics. In order to reveal the mechanical properties and influencing factors of LSAM-50 in depth, a numerical test method for the mechanical properties of the large particle size LSAM-50 asphalt mixture was developed, and a reasonable specimen size for LSAM-50 performance test was proposed by combining the numerical test and the indoor test. The results show that: LSAM-50 numerical test conditions are the calculation time step 10-3 s/step, the loading rate is 2 mm/min (uniaxial compression numerical test) and 50 mm/min (splitting numerical test) when LSAM-50 numerical experiment calculation rate and numerical experiment accuracy are better; after the size of the specimen reaches 200×160mm, the influence of the size effect is eliminated. The reasonable specimen size of LSAM-50 is Φ200mm×h160mm; the LSAM-50 numerical test method and the indoor test have low error Less than 10%.

Bearing characteristics and damage rules of regenerated rock mass

This study investigates the bearing characteristics and damage evolution of regenerative rock masses formed under varying geological conditions through uniaxial loading tests, numerical simulations, and theoretical derivations. Regenerative rock mass samples with different water-cement ratios and cementing materials were prepared, and the mechanical behavior during the loading process was analyzed. The results indicate that the secondary damage process can be divided into three stages: pre-peak, weakening, and friction. As the mechanical properties of the cementing matrix improve, the bearing capacity increases, and the failure mode transitions from ductile to brittle. A damage constitutive model incorporating the Weibull distribution and a damage correction coefficient is proposed to predict the mechanical strength of regenerative rock masses. Numerical simulations using Particle Flow Code 3D (PFC3D) reveal that enhanced mechanical properties of the cementing material lead to a shift from tensile to shear failure. This study provides theoretical and practical guidance for the stability control of regenerative rock mass engineering, offering new insights into the design of support systems for mining operations. The findings have significant implications for the recovery of shallow residual coal resources and the stability control of mining roadways.

Experimental Investigation of Marine Soil Stabilization with Recycled Aggregates and MgO: Implications for CO&lt;sub&gt;2&lt;/sub&gt; Sequestration

Dredged marine soils are increasingly recognized as a valuable resource amidst growing environmental concerns and the need for sustainable waste recycling. This study presents an innovative soil stabilization technique combining recycled aggregate (RA) and magnesium oxide (MgO), with a dual focus on enhancing soil properties and promoting carbon dioxide (CO2) sequestration. The stabilizing effects of RA and MgO were evaluated independently and synergistically under varied curing conditions and durations, with microstructural and mechanical properties analysed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and uniaxial tests. Carbonation experiments quantified CO2 fixation potential, demonstrating that the formation of hydration and carbonation products, in conjunction with the dynamic moisture content and pH conditions, played a significant role in enhancing the structural reinforcement of the soil. The combined RA-MgO treatment achieved superior mechanical stability (1.28-3.02 MPa) and a CO2 sequestration capacity of up to 11 g/kg without compromising performance. This study highlights the dual environmental and structural benefits of utilising RA and low-content MgO for marine soil stabilization, offering a sustainable pathway to reduce carbon emissions, promote waste recycling, and support resilient infrastructure development.

Investigating slope stability of multiple stopes prone to instability in the Ziluoyi iron ore mining site

The ore mining sites commonly experience slope instability, which is causing concern for the workers’ safety and the operation’s stability. Considering the Ziluoyi iron ore mining site as a case study, uniaxial compression strength and shear tests are performed on the lower disk peripheral rock, ore body, and upper disk peripheral rock, leading to the extraction of compressive strength and elastic modulus (lower disk: 77.7 MPa–9.093 GPa; ore body: 19.6 MPa–4.619 GPa; upper disk: 55.47 MPa–5.573 GPa). Further, using the Hoek–Brown criterion in conjunction with the Moher–Columb criterion, the cohesion and internal friction angle of various samples are appropriately determined (lower disk: 21.124 MPa–35.614°; ore body: 21.66 MPa–26.5°; upper disk: 42.916 MPa–25.743°). By employing an appropriate rock mass reduction model, its constants (m and s) and RMR score for the consisting layers (schist layer and ore body) of the three understudy slopes (Slope#1–Slope#3) are evaluated. An effective algorithm based on the Morgenstern–Price method is employed and its effectiveness is also proved by comparing its factor of safety results with those of Geo-Slope for various slope structures subjected to different loads. Subsequently, the stability analyses of various slopes are methodically examined by predicting the factor of safety values under multiple types of loading (i.e., self-weight + groundwater, slope self-weight + groundwater + blasting vibration force, and self-weight + groundwater + seismic force). The factor of safety values of the slopes pertinent to Slope#1/Slope#2/Slope#3 subjected to the above loading conditions are obtained as 1.354/1.273/1.188, 1.326/1.239/1.169, and 1.321/1.232/1.162, respectively. Upon comparing these results with those of a valid homeland specification, it becomes clear that the results are able to meet safety standards and ensure efficient mine operation.

Nosé-Hoover Integrators at-a-Glance: Barostat Integration Has a Demonstrable Effect on Uniaxial Tension Results of Solid Materials.

Molecular dynamics is a popular method for evaluating the tensile stress behaviors of many nanomaterials; however, few manuscripts include their thermostat and barostat damping parameters along with their methods. Here, we illustrate the demonstrable effect that barostat integration has on system dynamics during uniaxial testing under a Nosé-Hoover scheme. Three systems are tested: a 2D graphene sheet, a 3D continuous aluminum volume, and a 3D discontinuous polyvinyl alcohol volume. Isobaric-isothermal (NPT) and isochoric-isothermal (NVT) integration methods are intrinsically related, with high NPT barostat damping parameters converging on the NVT system. As a result, slight variations in barostat damping parameters may elicit different stress responses with higher damping parameters directly linked to increased levels of triaxial strain.

Experimental investigation on mechanical properties and strength criteria of frozen soft rock.

Excavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0.5, and 1.0 MPa) at different freezing temperatures (room temperature, -5°C, -10°C, and -15°C). Test results indicate that the frozen soft rocks show strain softening characteristics. The stress-strain curve changes from a straight line to a curve as deviatoric stress constantly increases, while it decreases abruptly after the deviatoric stress reaches the peak and is slightly affected by the freezing temperature. At the same temperature, shear strength increases at a rate of 5.6 MPa/°C with increasing confining pressure; as freezing temperature decreases, the shear strength increases at 0.34 MPa/°C, and cohesion increases at 0.6 MPa/°C. Under the same confining pressure, the failure strain of soft rock decreases with the decrease of temperature. The Mohr-Coulomb (M-C) criterion can accurately describe the failure process of frozen soft rocks in the pre-peak stage, with a correlation coefficient greater than 0.98. Within the test stress range, soft rocks display attenuated stable creep deformation. Acoustic emission (AE) tests were conducted to further verify that the soft rocks show shear failure under load, with a shear plane showing an angle of 45° with the horizontal. The research findings provide technical support and theoretical reference for studying rock mechanical properties as well as for designing and carrying out underground freezing of rocks in a low-temperature environment.

3D printing of TPMS microlattice: indentation characterisation and numerical analysis

ABSTRACT Mechanical metamaterials are emerging as an important tool in many engineering applications, where microarchitectured lattices have advantages of high strength-to-weight ratios, energy absorption capabilities and versatility in designed mechanical behaviours. Whilst a variety of microarchitectured lattices have been previously investigated for their mechanical properties, they have been mostly constrained to strut and plate-based designs and subjected to additional post-processing to modify their functionality. In this work, we demonstrate a novel approach utilising the two-photon polymerisation (2PP) method to generate complex, defect-free microarchitectured lattices. Unlike traditional methods, our technique allows for the direct fabrication of shell-based triply periodic minimal surfaces (TPMS) without requiring any additional post-processing. We utilise gyroid and diamond TPMS unit cells to perform uniaxial micro-compression testing to characterise their mechanical properties. In doing so, we gain insights into the mechanical behaviours of microlattices, with the finding that diamond cells possess superior stiffness and energy absorption potential compared to gyroid cells. To unravel the size-dependency property alterations at this scale, we further analyse a variety of bending beam samples and observed a strain rate-dependent mechanical behaviour attributable to the material's viscoelastic nature. We employ finite element analysis to enhance our understanding of the deformation mechanisms inherent in TPMS topologies, finding good agreement with measured mechanical properties. This work establishes a comprehensive framework that spans from design and geometry characterisation to robust microstructure testing using indentation, combined with comprehensive numerical simulation.

Long-term rutting prediction of gussasphalt steel bridge deck pavement based on comprehensive finite element modelling

ABSTRACT Gussasphalt is widely used for steel bridge deck pavements, but it is prone to rutting during the operational stage. This paper proposes a finite element-based method for predicting rutting in gussasphalt steel bridge deck pavements. Based on the Nanjing Yangtze River Fourth Bridge project, asphalt mixture specimens were prepared and tested in the laboratory. The viscoelastic-plastic constitutive model was fitted via dynamic modulus test and uniaxial repeated loading creep test results. Wheel track tests were conducted to validate the numerical model. The temperature gradient was obtained using actual environmental data and validated using actual data from buried thermocouples. Based on the equivalent conversion and simplification of traffic loads, the permanent deformation of the pavement layer was calculated using both the viscoelastic-plastic constitutive model and the time-hardening creep constitutive model. The viscoelastic-plastic constitutive model yields an average relative error of 25% and an absolute error of 0.57 mm, while the time-hardening creep constitutive model shows an average relative error of 40% and an absolute error of 1 mm. The results indicate that the viscoelastic-plastic constitutive model can more accurately predict the long-term rutting of the steel bridge deck pavement.

Effect of Age on the Biomechanical Properties of Porcine LCL.

The Lateral Collateral Ligament (LCL), one of the four major ligaments in the knee joint, resides on the outer aspect of the knee. It forms a vital connection between the femur and the fibula. The LCL's primary role is to provide stability against Varus forces, safeguarding the knee from undue rotation and tibial displacement. Uniaxial mechanical testing was conducted on the dog bone (DB) samples in this study. The porcine of different ages, from 3 months to 48 months (4 years) old, were used to analyse the effect of age. A constant head speed of 200 mm/s was applied throughout the tests to mimic strain-stress and damage responses at an initial strain rate of 13.3/s. The mechanical properties of LCL were evaluated, with a specific focus on the effect of age. The LMM (Linear Mixed Model) analysis revealed a marginally significant positive slope for Young's modulus (p = 0.0512) and a significant intercept (p = 0.0016); for Maximum Stress, a negative slope (p = 0.0346) and significant intercept (p < 0.0001); while Maximum Stretch showed a significant negative slope (p = 0.0007) and intercept (p < 0.0001), indicating the muscle reduces compliance and load-bearing capacity with age.

The Addition of MoO3 or SiO2 Nano-/Microfillers Thermally Stabilized and Mechanically Reinforce the PVDF-HFP/PVP Polymer Composite Thin Films

The properties of thin polymer films are influenced by the size of the fillers, their morphology, the surface properties and their distribution/interaction in the polymer matrix. In this work, thin polymer composite films with MoO3 or SiO2 nano and micro fillers in PVDF-HFP/PVP polymer matrix were successfully fabricated using the solvent casting method. The effects of different types, sizes and morphologies of the inorganic fillers on the crystallization of the PVDF-HFP polymer were investigated, as well as the effects on the thermal and mechanical properties of the composites. Scanning electron microscopy, ATR-FTIR spectroscopy, differential scanning calorimetry, nanoindentation and uniaxial mechanical tests were used for characterization. The results showed that MoO3 nanowires thermally stabilized the polymer matrix, induced crystallization of the PVDF-HFP polymer in all three polymorphs (α-, β-, γ-phase) and formed a geometrical network in the polymer matrix, resulting in the highest elastic moduli, hardness and Young’s modulus.

The Influence of Rubber Hysteresis on the Sliding Friction Coefficient During Contact Between Viscoelastic Bodies and a Hard Substrate

This paper describes research aimed at the experimental determination of the influence of rubber hysteresis on the friction coefficient between rubber samples for making soles and granite tiles. In the experiments, four types of shoe rubber with similar hardness and different hysteresis properties and two granite tiles with different roughnesses (smooth and anti-slip) were used. The determination of rubber hysteresis was carried out experimentally on a uniaxial testing machine. The friction coefficient was measured using a device specially developed for this type of test, which was based on the pulling force method, while the measurement conditions were based on the EN 13893:2011 standard. The friction coefficient was measured at two different speeds, 50 mm/s and 300 mm/s, with different surface conditions. Using regression analysis and the Taguchi method, the data obtained from the experiments were analyzed to determine the influence of parameters on the friction coefficient. The experimental research shows that different rubber mixtures with the same or similar hardness could have different hysteresis properties but also different friction properties.

Investigation into the time-dependent mechanical behavior of pre-stressed anchor bolts and fractured rock specimens under synchronized tensile loads

Pre-stressed anchor bolts serve as an effective means to reinforce fractured rock masses. The long-term efficacy of their anchoring function significantly impacts the safety throughout the entire lifecycle of rock engineering projects. Over time, fractured rock masses undergo creep deformation, which interacts synergistically with the time-dependent changes in the pre-stress of anchor bolts. In this work, we conduct uniaxial tensile tests and tensile creep tests on fractured rock specimens anchored by pre-stressed bolts, analyzing the coordinated deformation between the pre-stressed anchor bolts and the fractured specimens. Firstly, conventional uniaxial tensile tests were conducted on the pre-stressed anchorage specimen. The study found that the tensile strength of the anchored specimens was significantly higher than that of the unanchored specimens. Additionally, the ability of the specimens to withstand tensile stresses and deformation improved as pre-stress increased. Secondly, uniaxial tensile creep tests were conducted on the prestressed anchored specimens. The results indicate that, as the stress level increases, the creep strain continues to increase. The application of prestress can effectively limit the tensile deformation of the specimen and delay its damage time. The greater the pre-stress, the smaller the instantaneous strain and creep strain rate during the graded loading test. Finally, based on the synergistic deformation of pre-stressed anchor bolts and the creeping rock mass, we establish a constitutive model reflecting the creep properties of fractured rock mass and derive a theoretical viscoelastic creep formula for anchored rock mass under uniaxial tension. Comparing the creep model with the test results shows that this model is highly applicable and accurate in verifying the tensile creep deformation of prestressed anchorage specimens.

Improving Fatigue Life Prediction of Natural Rubber Using a Physics‐Informed Neural Network Model

ABSTRACTTraditional physical models and purely data‐driven approaches often struggle with small sample sizes and the complex effects of strain ratios. To overcome these challenges, this study integrates physical principles with machine learning techniques to improve fatigue life predictions for natural rubber (NR). A uniaxial fatigue test on NR was performed, generating data to construct a physical model. A physics‐informed neural network (PINN) model was subsequently developed, utilizing the fatigue life predicted by the physical model, along with engineering strain amplitude and strain ratio as input variables, whereas the experimentally observed fatigue life served as the output variable. The accuracy of the physical model, a data‐driven model, and the proposed PINN model was evaluated by comparing their predictions against measured fatigue life data. The findings demonstrate that the PINN model significantly enhances prediction accuracy, with its fatigue life estimates consistently falling within 1.5 times the measured values.

Modeling of the Stress-Strain Quality of Hydroentangled Nonwoven Fabrics

Hydroentanglement is a mechanical bonding process designed to produce nonwoven fabrics with appearances and textures that resemble woven and knitted fabrics. Eleven samples of hydroentangled nonwoven fabrics with different compositions and weights were subjected to a series of uniaxial stress-strain tests. Models, ranging from the simple Kelvin to the more complicated Kelvin–Vangheluwe, were fitted to the experimental data to find a generalized and universal model. In this model, a nonwoven fabric was considered a nonlinear viscoelastic material. The combination of Kelvin and Vangheluwe models resulted in an excellent fit to the uniaxial stress-strain curves. The model-predicted results almost overlapped with the experimental data, an indication of its excellent accuracy in predicting the mechanical behavior of nonwoven fabrics.

Active and passive material response of urinary bladder smooth muscle tissue in uniaxial and biaxial tensile testing.

The urinary bladder is a hollow organ that undergoes significant deformation as it receives, stores, and releases urine. To understand the organ mechanics, it is necessary to obtain information about the material properties of the tissues involved. In displacement-controlled tensile tests, tissue samples are mounted on a device that applies stretches to the tissue in one or more directions, resulting in a specific stress response. For this study, we performed uniaxial and biaxial stretch experiments on tissue samples (n = 36) from the body region of the porcine urinary bladder. We analyzed the stress-relaxation, activation dynamics, and passive and active stretch-stress response. Main findings of our experiments are: (1) For uniaxial and biaxial stretching, the time constants for stress-relaxation depend on the stretch amplitude, (2) biaxially stretched samples experienced slower activation with τact increasing by 163% compared to uniaxial stretching, (3) biaxial tests are characterized by reduced optimum stretches λopt by -18%, and (4) biaxial and uniaxial tests showed no significant difference in maximum active stresses σopt. To interpret the results, we present a continuum mechanical model based on a viscoelastic, isotropic solid extended by a set of active muscle fibers. Model predictions show that results (3) and (4) can be explained by a uniform distribution of fiber orientations and a specific shape of the active fiber stress-stretch relationship. This study highlights how deformation modes during tensile testing affects smooth muscle mechanics, proving insights for interpreting experimental data and improving organ modeling. STATEMENT OF SIGNIFICANCE: In this study, we examined the mechanical properties of porcine bladder smooth muscle using uniaxial and equibiaxial tensile tests. To our knowledge, this is the first instance where the active stress-stretch relationships of smooth muscle tissue have been analysed under equibiaxial stretch. The data collected offer a detailed understanding of the connection between deformation and active stress production, surpassing the insights provided by existing uniaxial tests in the literature. These findings are crucial for comprehending the physiology of smooth muscle tissue and for developing constitutive muscle models that can make more accurate predictions about the functionality of hollow organs in both health and disease. Additionally, our findings on smooth muscle active stress could aid in the creation of biomaterials that interact with or even replace natural muscle.

Knotless Suture Anchors Display Favorable Elongation but an Inferior Ultimate Failure Load Versus Titanium Suture Anchors and All-Suture Anchors: A Biomechanical Comparison in a Porcine Model.

Several types of suture anchors, which differ in their working principles, are available for fixation of ligamentous structures in knee surgery. How the choice of a suture anchor type influences the biomechanical stability of ligament fixation is largely unknown. To compare the biomechanical properties of different suture anchor designs regarding primary stability for tendon fixation and repair in medial collateral ligament (MCL) surgery. Controlled laboratory study. The primary stability of MCL fixation was assessed in a porcine model utilizing 1 of 3 suture anchor types: a 5.5-mm titanium suture anchor (TSA), a 2.8-mm all-suture anchor (ASA), or a 5.5-mm polyether ether ketone knotless suture anchor (KLSA). Primary stability was assessed using a uniaxial material testing machine. Cyclic loading at 50 N and 100 N was applied for 500 cycles each, followed by a load-to-failure test. After 500 cycles at 50 N, the KLSA (2.4 ± 0.3 mm) showed significantly (P < .05) reduced elongation in comparison to the TSA (4.0 ± 0.9 mm) and ASA (3.6 ± 0.7 mm), and after 500 cycles at 100 N, the KLSA (6.5 ± 1.4 mm) again showed significantly (P < .05) reduced elongation in comparison to the TSA (11.0 ± 2.2 mm) and ASA (12.0 ± 3.6 mm). However, the KLSA (213 ± 27 N) showed a significantly (P < .05) inferior ultimate failure load in comparison to the TSA (300 ± 20 N) and ASA (348 ± 23 N). In comparison to the TSA (113.0 ± 11.0 N/mm) and ASA (113.6 ± 14.4 N/mm), the KLSA (150.7 ± 11.6 N/mm) displayed the highest stiffness (P < .05). No significant differences were observed regarding yield load. KLSAs displayed significantly reduced elongation, at the cost of a reduced ultimate failure load, in comparison to TSAs and ASAs. Surgeons should be aware that differences exist between different suture anchor types regarding their biomechanical stability. KLSAs may be favorable for fixation of peripheral ligaments in knee surgery.

3D-printed suction clamps for tensile testing of brain tissue.

The conventional mounting of ultra-soft biological tissues often involves gluing it between two plates or manually tightening grips. Both methods demand delicate handling skills and are time-consuming. This study outlines the design and practical application of 3D-printed suction clamps for uniaxial tension tests on brain samples. Successful testing was defined by the absence of relevant slippage or the sample being drawn into the clamp. A total of 112 deer brain samples underwent testing using a universal testing machine after one freeze-thaw cycle. These samples were obtained from eight different brain regions. During sample preparation, 7 out of all samples failed. Among the 105 tests, 89 (85%) were successful. Of the 16 unsuccessful tests, 15 samples (14%) slipped, while only one sample (1%) was drawn into the clamp to an extent that testing became impossible. Medulla oblongata samples exhibited exceptionally high slippage at 38%, whereas samples from the temporal cortex, external capsule, and putamen had the lowest slippage in only one single case. In conclusion, suction clamps facilitate high-throughput testing through user-friendly and rapid sample mounting. Testing success is contingent on the specific brain site, with sample slippage being the primary reason for testing failures, while sample inspiration into the clamp is negligible.