This research investigates the effects of torsional moments on the mechanical behavior of thin-walled open-ended vertical pile foundations subjected to lateral wind loads. The aim of this research is to determine and quantify the errors using traditional design methods and provide more effective alternatives. The warping and torsion effect generated over the piles due to the resultant lateral load impact outside the shear center is analyzed in field tests. Complementarily, a two-dimensional finite element model based on the simple bending stress–strain state, as well as a three-dimensional finite element model considering torsional effects, were implemented and their results analyzed. Finally, a comparative analysis between the in-field lateral loading tests and the finite element model approaches was established by comparing load–displacement curves and using a non-linear Wrinkle model of the soil. Additionally, correlations between the experimental and finite element model errors for the cross-sections pile with a different torsional constant and torsional susceptibility index are shown. From the results, it has been ascertained that the slender thin-walled open-ended pile foundations are particularly sensitive to small load deviations from their center of gravity; this leads to the fact that the slenderer the load and the greater its eccentricity, the more it affects the torsion and warping of the pile. Calculation methodologies usually consider a simple in-plane bending behavior, which leads to errors between 44 and 58% in comparison with the experimental results obtained.

This research investigates the effects of torsional moments on the mechanical behavior of thin-walled open-ended vertical pile foundations subjected to lateral wind loads. The warping and torsion effect generated over the piles due to the resultant lateral load impact outside the shear center is analyzed in-field tests. Complementarily, a two-dimensional finite element model based on the simple bending stress-strain state as well as a three-dimensional finite element model considering torsional effects were implemented and their results analyzed. Finally, a comparative analysis between the in-field lateral loading tests and the finite element model approaches was established and correlations between the errors and the parameters of influence were highlighted. From the results, it has been ascertained that the slender thin-walled open-ended pile foundations are particularly sensitive to small load deviations from their center of gravity, this leads to the fact that the slenderer and the more eccentricity of the load, the more it affects the torsion and warping of the pile. Calculation methodologies usually consider a simple in-plane bending behavior which conducts to errors between 44 and 58% of the experimental results.

Most structures supporting solar panels are found on thin-walled metal piles partially driven into the ground, optimizing costs and construction time. These pile foundations are subjected to repetitive lateral loads from various external forces, such as wind, which can compromise the integrity of the pile-soil system. Given that the expected operational lifespan of photovoltaic solar plants is generally 20–30 years, predicting their service life under fatigue loads is crucial. This research analyzes the response of H-section piles to lateral fatigue loads in cohesive rigid soils through four field tests, subjected to load cycles of 55%, 72%, and 77% of the static failure load, corresponding to maximum loads of 25 kN, 32 kN, and 35 kN, respectively. Additionally, the effect of load cycles on the degradation of pile-soil adhesion is studied through two pull-out tests following cyclic tests. This study reveals that soil fatigue does not occur under repetitive loads and that soil stiffness remains constant once the cycles causing soil compaction have been overcome. Nevertheless, the accumulated plastic deflection of the soil increases steadily once soil compaction occurs due to cyclic loading. The implications of these results on the fatigue life of photovoltaic solar panel foundations are discussed.

Dental enamel is one of the strongest biomaterials found in nature, making its mechanical failure of significant interest to the biomaterials and dental communities. Recent studies on the mechanisms of enamel wear have yielded conflicting results, highlighting the need for more realistic experimental approaches. Here, we introduce a novel experimental methodology based on nanotechnology techniques and micromechanical/materials testing to simulate and characterize, for the first time, in vitro microwear caused by the sliding of artificial models of soft leaves containing phytolith particles against human dental enamel. While embedded phytoliths undergo mechanical degradation upon cyclic contacts, they increase the extent of pre-existing wear in enamel and decrease its mineral content. Surprisingly, the primary wear mechanism of enamel is ‘quasi-plastic’ (i.e. permanent) deformation enabled by failure of weak interphases, dominated at the microstructural scale. Mechanisms responsible for material removal in enamel at different length scales are identified and discussed. This research offers new insights into enamel failure that can further reveal information about an animal’s biology, behaviour, biomechanics and ecology, offering an interdisciplinary approach to the interface between the physical and life sciences.

Zirconia-reinforced lithium silicate (ZLS) is utilized as a material for prosthetic tooth crowns, offering enhanced strength compared to other dental glass-ceramics. In this study, we investigate a commercial ZLS material, provided in a fully crystallized form. We examine the effects of an optional post-processing heat treatment on micro-contact damage using controlled indentation tests simulating the primary modes of contact during chewing: axial and sliding. Our findings indicate that the heat treatment does not affect mechanical properties such as the elastic modulus, hardness and indentation fracture toughness. However, it does enhance the resistance to contact damage by fracture and chipping in both axial and sliding modes, as well as the resistance to crack initiation measured from sliding tests. This improvement is attributed to the refinement of the flaw population achieved through the heat treatment. The results are analysed using principles of contact and fracture mechanics theory, discussing their significance in prosthetic dentistry.

Motivation: Dental enamel possesses a unique anisotropic, heterogeneous hierarchical structure which enables a combination of high hardness and remarkable durability compared to other natural and synthetic biomaterials. Nevertheless, it undergoes mechanical degradation through fracture from concentrated overloads and/or progressive wear, both of which can compromise tooth function and longevity. Enamel wear is of particular interest to anthropology, as it is ubiquitous and enables researchers to discern the culture, behaviors, and ecologies of the study populations. Studies simulating dental wear in vitro often employ simplified loading configurations based on combinations of axial and lateral forces, which successfully reproduce the “classical” microwear features of pits and scratches, but do not capture the full complexity of in vivo loading conditions. Objectives: To conduct a preliminary in vitro investigation of previously underexplored rotationally induced occlusal mechanical wear in enamel. Methods: Cyclic contact tests combining compression (50 N) and rotation (30°) are applied to human enamel specimens using a testing machine with decoupled biaxial (axial‐torsion) actuators. Damage is characterized by electron and confocal microscopy. Results: Rotational forces produce abrasive wear with distinct microscopic damage patterns, involving transitions from quasi‐plastic to brittle damage modes with an increasing number of contact cycles. After 10 ⁴ cycles, the macrowear volume is 0.0023 mm ³ . Conclusions: Rotational microwear differs from “classical” pits and scratches associated with axial–lateral loading. Findings offer a framework for interpreting curved microscratches and provide a basis for future investigations. More broadly, they contribute to improving models of dental microwear and provide new insights in biomaterials science and anthropology.