Maximum Displacement Research Articles

Investigation of the Seismic Performance of a Multi-Story, Multi-Bay Special Truss Moment Steel Frame with X-Diagonal Shape Memory Alloy Bars

In this work, the seismic response of a multi-story, multi-bay special truss moment frame (STMF) with Ni-Ti shape memory alloys (SMAs) incorporated in the form of X-diagonal braces in the special segment is investigated. The diameter of the SMAs per diagonal in each floor was initially determined, considering the expected ultimate strength of the special segment, developed when the frame reaches its target drift and the desirable collapse mechanism, i.e., the formation of plastic hinges, according to the performance-based plastic design procedure. To further investigate the response of the structure with the SMAs incorporated, half the calculated SMA diameters were introduced. Continuing, three more cases were investigated: the mean value of the SMA diameter was introduced at each floor (case DC1), half the SMA diameter of case DC1 (case DC2), and twice the SMA diameter of case DC1 (case CD3). Dynamic time history analyses under seven benchmark earthquakes were conducted using commercial nonlinear Finite Element software (SeismoStruct 2024). Results were presented in the form of top-displacement time histories, the SMAs force–displacement curves, and maximum inter-story drifts, calculating also maximum SMA displacements. The analysis outcomes highlight the potential of the SMAs to be considered as a novel material in the seismic retrofit of steel structures. Both design approaches presented exhibit a certain amount of effectiveness, depending on the distribution, with the placement of the SMA bars and the seismic excitation considered. Further research is suggested to fully understand the capabilities of the use of SMAs as dissipation devices in steel structures.

Three-Dimensional Numerical Analysis of Seismic Response of Steel Frame–Core Wall Structure with Basement Considering Soil–Structure Interaction Effects

In recent years, numerous studies highlighted the crucial role of the soil–structure interaction (SSI) in the seismic performance of basement structures. However, there remains a limited understanding of how this interaction affects buildings with basement structures under varying site conditions. Based on the three-dimensional (3D) numerical analysis method, the influence of the SSI on the seismic response of high-rise steel frame–core wall (SFCW) structures situated on shallow-box foundations were investigated in this study. To further investigate the effects of the SSI and site conditions, three types of soil profiles—soft, medium, and hard—were considered, along with a fixed-foundation model. The results were compared in terms of the maximum lateral displacement, inter-story drift ratio (IDR), acceleration amplification coefficient, and tensile damage for the SFCW structure under different site conditions, with both fixed-base and shallow-box foundation configurations. The findings highlight that the site conditions significantly affected the seismic performance of the SFCW structure, particularly in the soft soil, which increased the lateral deflection and inter-story drift. Moreover, compared with non-pulse-like ground motion, pulse-like ground motion resulted in a higher acceleration amplification coefficient and greater structural response in the SFCW structure. The RC core wall–basement slab junction was a critical region of stress concentration that exhibited a high sensitivity to the site conditions. Additionally, the maximum IDRs showed a more significant variation at incidence angles between 20 and 30 degrees, with a more pronounced effect at a seismic input intensity of 0.3 g than at 0.2 g.

Dynamic behavior of high-speed maglev guideway girders with quadratically-varied cross-section

This study focuses on the numerical investigation on the coupling vibration responses of high-speed maglev vehicle-guideway system incorporated with guideway girders with quadratically-varied cross-section and the new generation high-speed maglev trains. Finite element model for the coupling vibration responses analysis of maglev vehicle-guideway system was established and validated against the existing field test results. With the verified model and program, a total of 5292 numerical models were included to comprehensively investigate the influences of cross-sectional geometries and span length of the guideway girder as well as the vehicle speed on the coupling vibration responses of high-speed maglev vehicle-guideway system. The coupling vibration responses, including impact coefficient, maximum suspension gap and maximum displacement of bogie as well as maximum displacement of the car-body, were analyzed. Recommendation on the dynamic performance indicator was proposed for the guideway girders with quadratically-varied cross-section. Prediction models regarding the impact coefficient and mid-span maximum acceleration of guideway girders with quadratically-varied cross-section were developed based on the Artificial Neural Network analysis method.

Analysis of the influence of bottom flow holes in control rod guide tubes on flow field and control rod displacement

During the operation of pressurized water reactors, flow-induced vibration issues are commonly encountered, where control rod components vibrate due to the impact of coolant flow, leading to wear, thereby posing a threat to the safe operation of the reactor. This paper conducts a detailed numerical simulation of the flow field and force distribution inside a full-scale lower control rod guide tube based on the CFD method. The fluid–structure interaction analysis is performed to reveal the influence of cross-flow under various operating conditions on the vibration and displacement of control rods. The research subject consists of 24 control rods, one continuous guide section, and six control rod guide cards. The lower part of the guide tube has two flow holes on each surface, with one assumed to be a cross-flow inlet and the others as outlets. The results indicate that when considering the cross-flow effect at the flow holes, 90 % of the coolant flows out from other flow holes at the bottom of the guide tube, resulting in increased transverse velocity at the bottom and the presence of numerous vortices. The magnitude and location of the force exerted on the control rod by coolant impact are correlated. The control rod closest to the inlet of the flow hole experiences the greatest force, approximately 5.35 times the average at other positions. At a cross-flow velocity of 0.4 m/s and a low frequency of 10 Hz, the maximum displacement of the control rod is 0.3355 mm.

A comprehensive investigation into the effect of vertical component of ground motion on response of sliding unanchored blocks

This study aims to quantify the effect of the vertical component of ground motion on the seismic response of sliding rigid blocks, in terms of maximum and residual displacements. A multi-stripe analysis approach is employed to examine the response with and without the vertical component under various levels of ground motion intensity. First, a parametric study is conducted using a Coulomb friction model with a constant coefficient of friction that does not account for any dependence of the friction coefficient on velocity or pressure. It is shown that the effect of the vertical component on maximum and residual displacement is more pronounced for ground motions that can barely initiate sliding. Moreover, the influence of the vertical component on the residual sliding displacement is higher than that on the maximum displacement. Subsequently, to account for the friction coefficient dependence on pressure and sliding velocity, two interface cases (steel-steel, and concrete-concrete) are analyzed. It is found that even when a variable coefficient of friction is used, the overall trends observed for a constant coefficient of friction do not change.

Self-centering rocking steel frame with column mid-height uplift: Experimental and numerical investigation

This paper proposes a self-centering rocking steel frame with column mid-height uplift (SCRSF-CMU) that exhibits high post-yield stiffness and energy dissipation capacity. The hysteretic performance of the SCRSF-CMU was investigated through cyclic loading tests. A numerical model of the SCRSF-CMU was established and validated against experimental results. Subsequently, the seismic performance of the SCRSF-CMU was compared with that of the self-centering rocking steel frame with column base uplift (SCRSF-CBU) using nonlinear time history analysis. Finally, the seismic responses of the SCRSF-CMU and SCRSF-CBU under varying earthquake intensities were analyzed using the endurance time analysis. The results indicate that the designed SCRSF-CMU demonstrates excellent lateral force resistance, energy dissipation, and self-centering capabilities. The rocking effect and the restoring force of the post-tensioned steel strands effectively controlled the residual lateral displacement of the specimens. The multi-scale numerical model of the SCRSF-CMU accurately captured its hysteretic behavior and deformation patterns. Compared to the SCRSF-CBU, the SCRSF-CMU exhibited superior rocking deformation capacity, post-yield stiffness, and hysteretic energy dissipation. Under MCE excitation, both SCRSF-CMU and SCRSF-CBU showed uniform inter-story drift distribution with minimal residual deformation, creating a satisfactory condition for the post-earthquake repair work if necessary. The high post-yield stiffness of the SCRSF-CMU was more effective in reducing both maximum and residual displacements. Endurance time analysis revealed that SCRSF-CMU and SCRSF-CBU exhibited relatively uniform inter-story drift distribution under SLE, DBE, and MCE earthquakes. Under FE excitation, the inter-story drift ratio of both structures were nearly identical; however, under DBE and MCE excitations, the maximum roof drift ratio and inter-story drift ratio of the SCRSF-CBU were larger, indicating that the SCRSF-CBU had higher deformation demands than the SCRSF-CMU.

Deep analysis of power regulation on fatigue loads and platform motion in floating wind turbines

The fatigue loads experienced by components and the motion of the platform in floating wind turbines are likely influenced by their operation within a limited power state; however, the corresponding effects remain inadequately understood. This study investigates a 5 MW semi-submersible floating wind turbine, aiming to provide a comprehensive analysis of fatigue loads on critical components and platform motion under various power regulation modes. To achieve this objective, we employed the NREL 5 MW semi-submersible wind turbine model, generated three-dimensional wind fields using TurbSim, and conducted dynamic simulations with OpenFAST, utilizing MLife software for post-processing of fatigue load analysis. We assessed the fatigue loads of four key components—the blade root, tower base, drivetrain, and mooring cables—alongside the platform motion under varying generator speeds, yaw angles, and active power levels. Additionally, correlation analysis was performed to explore the relationship between component fatigue loads and platform motion under different yaw conditions. The results demonstrate that both generator speed and yaw angle significantly influence fatigue loads and platform motion, while the effect of active power appears to be relatively minor. Specifically, an increase in generator speed markedly elevates fatigue loads on the blade root and drivetrain, while concurrently reducing loads on the tower base and certain mooring lines. The analysis further reveals that, under various yaw angles, the fatigue loads on symmetrically positioned mooring cables exhibit a symmetric response, impacting fatigue damage in the blade root and tower base moments. Moreover, the relationship between maximum horizontal platform displacement and fatigue loads varies. The findings of this study provide critical insights into the operational optimization of floating wind turbines.

Review Paper on Seismic Analysis of Multi-Storied Reinforced Concrete Building with Fluid Viscous Dampers

Abstract: Frequent earthquakes around the world and the large number of buildings at risk have made it essential to focus on controlling how structures respond to these events. This demand has driven the increased use of structural response control methods globally. This study investigates the seismic performance of multi-storied Reinforced Concrete (RC) Buildings, distinguishing between Regular and Irregular Plan , with a focus on the role of Fluid Viscous Dampers (FVDs). The study aims to quantify the improvements in seismic resilience provided by these damping devices in mitigating the adverse effects of seismic events. Buildings having Regular and Irregular Plans are analyzed, with and without FVD using ETABS2018. The story responses in terms of Pseudo Spectral Accelerations, Maximum Displacement, Story Drift and Story Shear have been compared. The results of the Time History Analysis represent the effectiveness of dampers in improving the structural response and the damping demand on structural systems

Wall Deflection and Ground Surface Settlement due to Braced Deep Excavation in Soft-Soil Ground

An extensive database comprising more than 1,100 case histories of wall displacements and ground settlements due to deep excavations in soft soils created by Long, Moormann, and Wang et al. (2009) was analyzed. The applicability of the criteria for maximum lateral displacements and ground settlements using their database was analyzed. When excavation work is conducted under ground conditions where seaweed cohesive soil is distributed thickly, excessive horizontal displacement is expected to occur owing to low undrained shear strengths. Therefore, ground reinforcement was performed by applying a reinforcement method on the excavation side to secure a stability factor against a basal heave that exceeds 3.0. When using this method, applying the management standard for the maximum horizontal displacement, i.e., 0.3%H of the retaining wall, as the limit value is considered appropriate. This is expected to minimize the horizontal displacement of the retaining wall and the subsidence of the background during excavation work.

Innovative design and process simulation of aviation bracket based on topology optimization and additive manufacturing

Abstract In this paper, topology optimization(TO) and laser powder bed fusion (LPBF) technology were combined to explore the key technology of parts integration design and manufacturing oriented to performance, structure and manufacturing process. With the help of topology optimization(TO), the lightweight design of the aviation bracket achieved the weight loss goal of 87.69% in this work. The thermophysical properties of TC4 were calculated by thermodynamic calculation, and the temperatue interval of Laser Powder Bed Fusion for TC4 is 1800 ℃- 3000 ℃ was determined . Additionally, the LPBF macro-scale simulation was carried out. The results showed that the maximum temperature in the printing process is lower than 2500℃, and the maximum displacement is 4.87 mm, which only appears in the non-design space. Finally, the safety factor and maximum displacement of aviation bracket are 1.3 and 0.8 mm, and the maximum Mises stress is 654 MPa, all of which meet the design requirements.

Low-velocity crashworthiness and optimization of a crash box filled with modularized graded honeycomb

PurposeGraded honeycombs are materials that exhibit better energy absorption performance compared to uniform honeycombs without adding additional weight. This paper introduces a novel modularized graded honeycomb into a commercial crash box to improve its crashworthiness.Design/methodology/approachA modularized graded honeycomb is inserted into a commercial crash box to develop a novel crash box. Finite element analyses are conducted to investigate the crashworthiness. Pareto cumulative influence analysis is conducted to rank the effects of design parameters on crashworthiness. A surrogate model-based multi-objective optimization is carried out to improve energy absorption while limiting the impact peak force. An optimal Pareto solution set is obtained.FindingsModularized honeycomb-filled crash box outperforms that of its corresponding uniform honeycomb-filled crash box and empty crash box in resisting impact. Pareto cumulative influence analysis reveals that for most crashworthiness indicators, cell-wall thicknesses of crash box tube contribute the most, followed by average relative density and graded coefficient of modularized honeycomb (MH). Graded coefficient contributes nearly 10% on mean force and maximum displacement, but it has insignificant influence on peak force and weight. Optimization results show that the optimal designs can not only absorb more energy but also limit the peak force compared with those of uniform honeycomb-filled crash box.Originality/valueThis paper fills a MH into a commercial crash box to propose a novel crash box and demonstrates the positive impact of modularized design on crashworthiness compared with that of uniform honeycomb-filled crash box. Moreover, modularizing honeycomb does not change the weight of the filler, and thus, the novel crash box would benefit development of crash box with lightweight and excellent energy absorption capacity.

Right atrio-ventricular strain as a predictor of death in left-sided heart failure

Abstract Background Right ventricular (RV) strain is an established outcome predictor in heart failure (HF). However, the role of right atrial (RA) strain in the setting of left-sided HF is incompletely understood. Purpose We sought to evaluate the RV, RA and combined right atrio-ventricular (RAV) strain using speckle-tracking echocardiography in a cohort of patients with left-sided HF and to assess their prognostic role. Methods 121 consecutive patients (mean age 59±14 years, 74% men) with HF with reduced ejection fraction (HFrEF) referred to our echocardiography department were prospectively enrolled. The main endpoint was all-cause death. RV strain was measured as the average longitudinal strain of the basal, mid, and apical segments of the RV free wall and was reported as a positive value, thus a lower RV strain reflecting a greater longitudinal dysfunction. RA strain was defined as the maximal longitudinal displacement of the atrial wall at end-systole, corresponding to atrial reservoir function. RAV strain was defined as the sum of RV strain and RA strain. Results During a median follow-up of 19±11 months, 26 patients (21%) died. Patients who reached the endpoint had lower left ventricular ejection fraction (LVEF) (21±7% vs. 26±7%, p=0.001), lower tricuspid annular plane systolic excursion (16±3 vs. 18±5, p=0.02) and lower RA strain (13± 10% vs. 18±11%, p=0.03). In univariable Cox regression, RV, RA and RAV strain were all predictors of death: HR=1.05 [95% CI, 1.00-1.11], p=0.045 for RV strain, HR=0.95 [95% CI, 0.91-0.99], p=0.02 for RA strain, HR=0.97 [95% CI, 0.94-0.99], p=0.01 for RAV strain. We constructed a multivariable model with well-established event predictors in HFrEF and one strain index at a time. After adjustment for LVEF, maximal left atrial volume, tricuspid regurgitation severity and pulmonary artery systolic pressure, only RAV strain remained an independent predictor of death (HR=0.97 [95% CI, 0.94-1.00], p=0.04), while RV strain and RA strain did not (p=0.07 for both). LVEF did not emerge as a predictor of death in multivariable regression (p=0.57). Conclusion In left-sided HF, RV and RA strain were predictors of death. Combining the longitudinal strain of both right heart chambers might improve risk stratification, since RAV strain remained the only independent predictor of adverse outcome after adjustment for confounders.

Experimental study and numerical analysis of a novel serrated-and-plate truss structure

High-speed rail station has extensive span and height, making daylighting a challenge. This paper proposes the serrated-and-plate truss structure (SPTS) to improve station daylighting. SPTS combines a serrated truss structure (STS) for daylighting and a plate truss structure (PTS) for lateral stability and deformation resistance. A downscaled SPTS with support-loading system is designed and built to test mechanical properties. It has 264 stress and 19 displacement measuring points, tested under four vertical and two horizontal load cases. Maximal stress and displacement are 150.7 MPa and 5.07 mm, with peak chord axial force and column base bending moment of 13.5 kN and 663.7 kN mm. Simulated and measured results match well, confirming the numerical method's accuracy. Thermal effects of SPTS are studied via conventical and extreme thermal analyses, with stress and displacement well below limits. Seismic spectrum and time-history analyses indicate SPTS stress and deformation at 63.9 % and 68.3 % of limits. Comparative analysis across 64 load cases reveal that STS is significantly less stable and resistant to deformation than SPTS, validating PTS's boundary constraint effects. Experimental and numerical studies confirm SPTS's engineering applicability and provide valuable references for similar truss structure research.

Analytical and Finite Element Analysis of the Rolling Force for the Three-Roller Cylindrical Bending Process

In the roll bending process, the rolling force acting on the roller shafts is one of the most important parameters since, on the one hand, it determines the process settings including the pre-loading, and, on the other hand, its distribution and size may affect the integrity of both the bending system and the final product. In this study, the three-roller bending process was modeled using a two-dimensional plane–strain finite element method, and the rolling force was determined as a function of plate thickness, upper roller diameter, and yield strength for various API steel grades. Based on the numerical simulation results, a critical bending angle of 41° was identified and the rolling systems were divided into two categories, of less than or equal to, and greater than 41°, and an analytical model for predicting the maximum rolling force was developed for each category. To determine the optimal pre-tensioning force, two optimization formulations were proposed by minimizing the maximum equivalent stress and the absolute maximum displacement. The rolling forces predicted by the analytical models were found to be in good agreement with the numerical simulation results, with relative errors generally less than 10%. The predictive analytical models developed in this study capture well the complex deformation behavior that occurs during the roll bending process of steel plates, providing guidelines and predictions for industrial applications of this process.

Failure analysis of multi-span masonry arch bridges using combination of point cloud data and three-dimensional numerical modeling

Historical structures, including historical bridges, are part of cultural heritage, conveying the traces and characteristic features of past civilizations. To protect historical structures, it is necessary to prepare their 3D photogrammetric documentation, determine detailed geometric and material properties and perform computer-aided structural analysis using appropriate modeling techniques. The aim of this study is to present an effective, reliable and fast multidisciplinary approach for the analysis of historical masonry bridges. The aforementioned approach was illustrated with an example of the historical Halilviran masonry arch bridge and its behavior under possible loadings. Terrestrial laser scanning (TLS) was used to determine the bridge geometry with high accuracy. Point cloud data obtained from TLS was simplified and a three-dimensional CAD-based solid model of the structure was created. The Halilviran Bridge case study summarized in this report was conducted to examine the technical feasibility of using la¬ser scanning technologies for obtaining as-built records for similar historic bridges. A secondary objective was to identify other applications of this technology, notably for other transportation structures, and use numerical methods to assess the seismic behavior and failure model of the bridge. The seismic behavior of the bridge was examined using a finite-element- based macromodeling technique. Nonlinear dynamic analyses were carried out subsequently to identify the most susceptible regions of the bridge. Interpretation of the results, presented in the form of contour plots illustrating tensile damage and maximum displacements, offered a comprehensive depiction of the seismic response across the entire bridge. The methodology employed in this investigation can be viewed as a robust framework for evaluating the seismic response and potential failure of historical structures.

Seismic behavior of base isolated precast frame

The performance of the base-isolated precast frame is examined for both near-field and far-field earthquakes. For comparison, the corresponding base isolated monolithic frame is analyzed. The frames are isolated using a friction pendulum system (FPS), which is appropriately designed to take up the vertical load coming on the frames. The same isolators are provided for the monolithic and precast frames. Two types of precast frames are considered, namely frames with emulated and non-emulated connections. An ensemble of 7 different earthquakes is used for each type of earthquake to obtain the average responses, which include maximum base shear, maximum acceleration, maximum top story displacement, and maximum inter-story drift ratio (MIDR). SAP2000 is used for the non-linear time history analysis of the frames for different earthquakes. The studies are made for three levels of PGA, namely 0.4 g, 0.6 g, and 0.8 g. The study shows that a significant reduction in base shear, top story displacement and MIDR is achieved by base isolating the precast frames. However, the corresponding base isolated monolithic frame offers more reductions in response especially for MIDR. Of the two types of precast frames, the one with emulated connection shows marginally higher reductions of response as compared to the non-emulated connection. Further, the percentage reductions in responses in main shock and after shock remain almost the same for all cases.

Study on field and numerical analysis of karst collapse as railway hazard

The vulnerability of karst ecosystems and the weak mechanical performance of caves pose hidden risks in railways, leading to increased karst collapses. To analyse karst collapse as a railway hazard, the Beijing–Guangzhou railway line in China was selected to identify karst features, using the multi-source frequency domain method because of its operational advantages. Abaqus was also used to numerically analyse the factors (dynamic loading, groundwater fluctuations, over-burden thickness) affecting the collapse mechanism. The study reveals diverse stratigraphy, transitioning from a Quaternary layer to stable rock formations. A notable finding is that the presence of a karst cavity in the railway embankment significantly increases the vertical dynamic displacements, particularly within the soil layer, by 72%, highlighting the significant impact of karst sections on soil dynamics. The study also reveals that due to the groundwater table fluctuations from the subsoil surface to the subgrade surface, the maximum displacement increases by 73% in the subgrade section of the railway embankment. The authors consider soil overburden thickness to validate confirmation of reliability through field data and theoretical study. The findings offer crucial insights for managing karst hazards, enhancing railway safety and ensuring durable infrastructure in challenging geological conditions.

The phosphodiester dissociative hydrolysis of a DNA model promoted by metal dications.

Phosphodiester bonds, which form the backbone of DNA, are highly stable in the absence of catalysts. This stability is crucial for maintaining the integrity of genetic information. However, when exposed to catalytic agents, these bonds become susceptible to cleavage. In this study, we investigated the role of different metal dications (Ca2⁺, Mg2⁺, Zn2⁺, Mn2⁺, and Cu2⁺) in promoting the hydrolysis of phosphodiester bonds. A minimal DNA model was constructed using two pyrimidine nucleobases (cytosine and thymine), two deoxyribose units, one phosphate group, and one metallic dication coordinated by six water molecules. The results highlight that Cu2⁺ is the most efficient in lowering the energy barrier for bond cleavage, with an energy barrier of 183kJ/mol, compared to higher barriers for metals like Zn2⁺ (202kJ/mol), Mn2⁺ (202kJ/mol), Mg2⁺ (210kJ/mol), and Ca2⁺ (223kJ/mol). Understanding the interaction between these metal ions and phosphodiester bonds offers insight into DNA stability and organic data storage systems. DFT calculations were employed using Gaussian 16 software, applying the B3LYP hybrid functional with def2-SVP basis sets and GD3BJ dispersion corrections. Full geometry optimizations were performed for the initial and transition states, followed by identifying energy barriers associated with phosphodiester bond cleavage. The optimization criteria included maximum force, root-mean-square force, displacement, and energy convergence thresholds.

Pelvic tilt and stiffness of the muscles stabilising the lumbo-pelvic-hip (LPH) complex in tensiomyography examination.

The objective of the study was to initially validate the hypothesis about the relationship between the pelvic tilt angle in the saggital plane and the functional state of muscles stabilising the lumbo-pelvic-hip (LPH) complex expressed as a change in their stiffness in a tensiomyography examination. Forty five women aged 19-30 years took part in an observational (cross-sectional) study. The examination involved measurements using the tensiomyography method (TMG). The stiffness of muscles stabilising the LPH complex expressed as a maximal muscle displacement (Dm variable) was assessed and the relationship between muscle stiffness and the value of the pelvic tilt (PT) in the sagittal plane was determined. The analysis showed significant differences in the values of medians of the muscle displacement (Dm) values in groups identified in terms of the value of pelvic tilt (Table 1) for Erector Spinae (ES) muscles (p = 0.0012), Gluteus Maximus (GM) muscles (p = 0.0004), Rectus Abdominis (RA) muscles (p = 0.0005), Obliquus abdominis externus (OAE) muscles (p = 0.0002*) and Rectus Femoris (RF) muscles (p = 0.0071). The results of the correlation analysis performed using the Spearman rho correlation coefficient between the value of pelvic tilt and muscle stiffness (Dm) show the following significant relations for ES muscles (p = 0<0.0001), GM muscles (p<0.0001), RA muscles (p<0.0001) and OAE muscles (p<0.0001). However, a clear direction of changes in stiffness in accordance with the description of relations defined as Lower Crossed Syndrome was not confirmed. A tensiomyographic examination did not show clear relations between the value of pelvic tilt and stiffness of muscles stabilising the lumbar-pelvic-hip complex. The mechanism of Lower Crossed Syndrome (LCS) may be not the only model explaining the relations between musculofascial structures of the hip-lumbar area. The implications of the LCS should not be the only basis for the therapy of disorders resulting from an incorrect position of the pelvis in the sagittal plane.

A 3-D modelling of monopile behaviour under laterally applied loading

Deploying higher-capacity offshore wind turbines to meet the growing energy demand poses a significant challenge in designing their foundations. Monopiles currently constitute 80% of the foundation installations for these turbines. This study utilizes a nonlinear three-dimensional (3D) finite element model to explore the behavior of monopiles underpinning a five megawatt wind turbine under horizontal loads. The findings reveal that the performance of monopiles is influenced by the strength of the soil and the ratio of pile depth of embedment to diameter (L/D). Examination of flexural bending profiles at/close to failure loads demonstrates the flexible behavior of monopiles, even with a low L/D ratio. The L/D ratio exhibits varying degrees of impact on the normalized ultimate lateral capacity of monopiles, with a notable effect observed in soft clays, resulting in an increase of up to five times for L/D ratios ranging from 3.33 to 13.33. Stiff clays show comparatively lesser effects. Under serviceability loading, an increase in the L/D ratio leads to a 3–6% rise in the maximum flexural moment of monopiles, while the maximum shear force experiences a decrease of 20–30%. Furthermore, a significant reduction, up to five-fold, in the maximum tower tip displacements and rotations at the mudline is observed with an increasing L/D ratio. However, this reduction is more pronounced for higher foundation rigidity.