Biomechanical performance of shock wave interventions on the knot after rotator cuff repair.

Nonlinear friction compensation and loading tracking control strategy for geotechnical triaxial dynamic and static loading based on iterative learning and dynamic surface inversion control

Plastic rotation limits of cold-formed steel hollow sections with moderate heat treatment under combined compression and cyclic lateral loads

Seismic performance and damage assessment of GFRP-steel composite tube confined columns under lateral cyclic load

The use of energy piles has grown significantly due to their environmental and economic benefits. These structures serve both as building foundations and as integrated geothermal systems, where pipes embedded within the piles circulate a heat-carrying fluid. This system extracts heat from the ground in winter and injects it back during summer, providing heating and cooling for the building. During operation, cyclic thermo-hydro-mechanical (THM) loads are induced in the surrounding soil, which can affect pile performance. Predicting these effects is challenging because of the coupled nature of THM interactions; for instance, changes in temperature will produce a mechanical response. Therefore, robust constitutive models and their proper validation are indispensable for understanding this behavior from a numerical perspective. In this study, a coupled thermo-hydro-mechanical hypoplastic constitutive model (THM-hypo-ISI) was employed for the finite element simulation of energy piles. The constitutive model was incorporated in the open-source finite element software OpenGeoSys for coupled thermo-hydro-mechanical processes. Subsequently, centrifuge experiments of energy piles subjected to cyclic thermal loading in fine-grained soils were simulated in the program. The simulation results indicate that the constitutive model effectively captures the cyclic thermo-hydro-mechanical behavior of fine-grained soils at different over-consolidation ratios. However, some limitations remain and are further discussed. • The proposed coupled thermo-hydro-mechanical hypoplastic constitutive model is able to capture the behaviour of energy piles. • The proposed coupled thermo-hydro-mechanical hypoplastic constitutive model describes the dependency of temperature on the response of fine-grained soils. • The proposed coupled thermo-hydro-mechanical hypoplastic constitutive model reproduced the soil response behaviour when subjected to cyclic thermo mechanical loading.

The paper deals with experimental and numerical characterization of the shear-dominated damage mechanism under ultra-low-cycle loading conditions. A universal uniaxial shear specimen for sheet metal with a double notch is proposed, enabling large deformation without rotation or buckling under both monotonic and cyclic loading. To investigate the influence of different shear loading histories on plasticity, damage, and fracture behavior, various cyclic loading patterns with overload and increased loading have been designed, considering both loading paths and amplitudes. Numerical analysis with a novel anisotropic cyclic plastic-damage continuum model has been performed and compared with experimental observations, including force–displacement responses and local strain fields obtained by the DIC technique. For the cyclic plastic model, a combined isotropic-kinematic hardening law within a modified Chaboche framework is proposed to describe plastic deformation under large strains. Compared to the scalar-based damage model, a damage strain rate tensor within the damage evolution law is employed to capture the shear damage mechanism caused by the growth and coalescence of micro-shear-cracks. Moreover, SEM is employed to characterize the fracture surface features at the micro-level, thereby verifying the proposed damage mechanism. • Novel uniaxial shear specimen for large cyclic deformation without rotation or buckling. • Newly designed shear cyclic experiments with overload and increased load patterns. • Shear-dominated damage mechanism under reverse loading conditions. • An advanced anisotropic cyclic plastic-damage continuum model. • DIC and SEM characterize macroscopic force–displacement, local strains, and microstructures.

Tensile fatigue evolution in sandstone under lower cyclic stress: Coupled Brazilian disc experiments and enhanced mesoscale damage modeling

Shock absorption is often mentioned as one of the functions of the meniscus, but consensus is lacking. The first objective of this study was to adopt adequate test methods for evaluating shock-absorbing and damping characteristics of the human knee joint and, more specifically, the meniscus. Secondly, the shock-absorbing effect of a novel medial meniscus prosthesis was investigated. Six cadaveric knee joints were subjected to a droptower experiment, where impact energies of 1.8, 3.5 and 5.3J were respectively applied on the femur. Outcome measures were the peak force measured under the tibia and loss factor η, which represents the ratio between dissipated and elastically stored energy. Both outcomes were compared between different medial meniscal conditions: Native meniscus, posterior root tear, total meniscectomy and meniscus prosthesis. In addition, all conditions were evaluated during sinusoidal loading at different frequencies (dynamic mechanical analysis; DMA), where a comparable loss factor tan δ was calculated from the phase lag between applied force and measured displacement. Finally, energy loss was directly quantified using the loop area of the hysteresis curves. Mean tibial peak forces increased after meniscectomy by up to 7%, although the difference was not statistically significant at the lowest impact energy. The meniscus prosthesis reduced the impact force in all cases, to the native level or lower. Impact loss factor η indicated similar effects on knee joint damping but yielded less significant differences. In the DMA, no significant differences in loss factor tan δ were found between the native menisci and the meniscus prosthesis. After meniscectomy, the DMA loss factor was always lowest, although not all differences were statistically significant. Meniscectomy also resulted in a reduction of energy loss compared to the intact condition. The prosthesis was able to increase energy loss, but not fully to the native level. From a clinical and biomechanical perspective, the meniscus has multiple different functions in the knee joint. This study demonstrated that the native meniscus and the meniscus prosthesis are both shock-absorbers, with the prosthesis performing better at lower impact energies. Meniscectomy reduces damping of the knee joint during cyclic loading, whereas the meniscus prosthesis has the capacity to largely restore the damping characteristics of the knee joint.

• Creep–fatigue tests of F82H at 550 °C clarified εpp constancy and εpc increase with holding time per cycle. • Stress relaxation behavior was independent of holding time per cycle and expressed by a unified constitutive law. • SRP constants for εpc were identified, enabling lifetime prediction within a factor of two. • A predictive model integrating SRP, relaxation law, and hysteresis geometry estimates lifetime for any arbitrary holding time per cycle. F82H, a reduced-activation ferritic/martensitic steel, is a key structural candidate for fusion breeding blankets, where components experience simultaneous high‑temperature creep and cyclic loading. This study evaluates its creep–fatigue (CF) behavior at 550 °C under a total strain range of 1.00% and proposes a predictive framework for CF lifetime estimation. CF tests with compression holding showed progressive lifetime reduction with increasing holding time per cycle. This study focused on two specific types of inelastic strains: plastic strain (εpp), which occurs due to tension and compression loads, and creep strain (εpc), which develops when a material is held under peak stress over time. It revealed that εpp remained constant, while εpc increased with dwell time. Stress relaxation behavior was independent of holding time and described by a unified constitutive relation. Material constants for εpc were identified, enabling the application of the strain‑range partitioning (SRP) method, which accurately reproduced experimental lifetimes within a factor of two. By integrating SRP, stress‑relaxation modeling, and hysteresis‑loop geometry, a master curve was constructed to predict CF lifetime for arbitrary holding times. The approach offers an efficient tool for CF assessment of fusion structural materials.

Fatigue cracking in steel structures poses a significant threat to their long-term performance and reduces their fatigue life. This study examines the effect of a repair intervention using ultrahigh-modulus carbon fiber–reinforced polymer (CFRP) bonded plates applied at various stages of fatigue crack propagation and its impact on extending the remaining fatigue life. The study also investigates the effect of CFRP bond length on crack growth rates and strain distributions. Bond lengths ranged from 0.5 to 2.4 times the effective development length (75–350 mm). Machined notches simulated initial defects, and cyclic loading was applied before and after retrofitting to control damage levels. Crack growth rates were quantified using beach marking, while strain concentrations and profiles were measured using distributed fiber optic sensing. The results show that CFRP repair is effective in increasing the fatigue life of a structure. For a CFRP plate with a 225 mm bond length, the remaining fatigue life extension ratio increased from 3.2 when intervention occurred at the onset of crack propagation (i.e., 25% area loss in the notched plate) to 7.2 when intervention occurred late in life, at 95% of the total cycles to failure (59% area loss) of the control samples. However, if assessment is based on increase in total cycles (i.e., pre- plus postrepair), results show a reduction in effectiveness at late intervention.

Collared Triple Taper Stems Have Superior Biomechanical Characteristics in Compromised Bone.

Finite element analysis of shot-sleeves behavior used in high-pressure die-casting process under cyclic thermo-mechanical loading

Seismic behaviors of precast sidewall-bottom slab joints of U-bar connections with UHPC permanent formwork in precast subway station structures

Study on damage characteristics of early-age steel fiber shotcrete under high-temperature variable-temperature curing and cyclic impact loading

Floating offshore wind turbines (FOWTs) are increasingly exposed to tropical cyclone (TC) hazards, which impose severe cyclic and transient loads on structural components. The complex marine environment leads to continuous corrosion-fatigue (CF) deterioration, gradually weakening the typhoon resistance and increasing system fragility over time. This study proposes a probabilistic framework for evaluating the reliability and vulnerability of FOWT flange bolted connections under typhoon conditions while accounting for CF-induced degradation. The framework integrates long-term environmental characterization, TC-induced wind-wave field modeling, a probabilistic CF model, and structural dynamic analysis. It is applied to assess the vulnerability and risk of a semi-submersible wind turbine. The results indicate that CF degradation leads to a reduction of flange-connection bending and axial resistances to approximately 20% and 40%, respectively. The system reliability declines rapidly under the combined effects of CF and typhoon loading, with flange connections exhibiting pronounced susceptibility to coupled cyclic and transient extremes. Moreover, the failure-probability distribution progressively shifts toward lower load levels with increasing deterioration, indicating that typhoon-induced stress amplification markedly reduces the structural safety. The cumulative system risk rises monotonically throughout service life, emphasizing the importance of accounting for long-term CF deterioration in resilience-oriented maintenance strategies for FOWTs operating in typhoon-prone regions. • Developed a probabilistic framework for FOWT typhoon–CF vulnerability. • Integrated wind–wave modeling with corrosion–fatigue crack evolution. • Coupled resistance degradation with dynamic typhoon response analysis. • Applied multi-mode reliability and risk assessment for flange connections.

Dynamic stimulation of piezoelectric scaffolds enhances osteogenesis-related biological responses via electro-mechanical sensitive channels and cytoskeletal remodeling.

A novel adhesive joint test is proposed and evaluated for enhanced adhesive system selection. This method employs a simple joint geometry specimen adaptable to standard dynamic mechanical thermal analysis (DMTA) equipment. The joint configuration enables versatile mixed loading under controlled environmental conditions (temperature and humidity), whilst subject to cyclic loading. Its compact size facilitates accelerated aging studies compared to conventional methods. Comparative analysis with single lap shear (SLS) joint testing demonstrates the new method's potential for superior or equivalent load and mode discrimination, while offering accelerated testing and deeper insights into substrate-adhesive interactions, i.e., variable stress states can be imposed on the adhesive layer, based on the location of the adhesive bondline, to tailor the stresses acting in the adhesive layer to better match stresses produced by service loads. Additionally, the new accelerated fatigue test method should provide complimentary data, such as the stiffness of adhesive joints, to traditional (and often simplistic) performance indicators, such as SLS performance. This parameter is particularly relevant to bonded engineering components, as the stiffness of adhesive joints is related with the fatigue performance of engineering components.

Experimental investigation of pile anchors in sand under inclined cyclic loading for TLP supported floating offshore wind turbines

Biomechanical evaluation of cemented femoral stem constructs with single and double cerclage stabilization of proximal fissures in canine cadaveric femora.

Biomechanical performance of three suture fixation techniques for proximal biceps tenodesis: a human cadaveric study.