Diagonal Force Research Articles

Optimization of cable-stayed force for asymmetric single tower cable-stayed bridge formation based on improved particle swarm algorithm

PurposeThis paper aims to optimize cable-stayed force in asymmetric one-tower cable-stayed bridge formation using an improved particle swarm algorithm. It compares results with the traditional unconstrained minimum bending energy method.Design/methodology/approachThis paper proposes an improved particle swarm algorithm to optimize cable-stayed force in bridge formation. It formulates a quadratic programming mathematical model considering the sum of bending energies of the main girder and bridge tower as the objective function. Constraints include displacements, stresses, cable-stayed force, and uniformity. The algorithm is applied to optimize the formation of an asymmetrical single-tower cable-stayed bridge, combining it with the finite element method.FindingsThe study’s findings reveal significant improvements over the minimum bending energy method. Results show that the structural displacement and internal force are within constraints, the maximum bending moment of the main girder decreases, resulting in smoother linear shape and more even internal force distribution. Additionally, the tower top offset decreases, and the bending moment change at the tower-beam junction is reduced. Moreover, diagonal cable force and cable force increase uniformly with cable length growth.Originality/valueThe improved particle swarm algorithm offers simplicity, effectiveness, and practicality in optimizing bridge-forming cable-staying force. It eliminates the need for arbitrary manual cable adjustments seen in traditional methods and effectively addresses the optimization challenge in asymmetric cable-stayed bridges.

Behavior of ultra-high-performance concrete deep beams reinforced by basalt fibers

Abstract Deep beams are crucial for construction projects due to their load-carrying capacity, shear resistance, and architectural adaptability. Ultra-high strength concrete and ultra-high-performance concrete (UHPC) are used in their production. Basalt fiber is used as an alternative due to its corrosion resistance, tensile strength, and thermal stability. This study investigates the behavior of UHPC deep beams reinforced with basalt fibers. Three sets of 11 specimens were constructed without transverse reinforcement and reinforced with either fibers or steel fibers. The study also analyzes the impact of parameters like shear strength capacity, crack development, and load-deflection behavior on UHPC deep beams. The study discovered that the inclusion of basalt fibers in UHPC deep beam can effectively postpone the onset of diagonal cracks. Incorporating basalt fiber at concentrations of 0.5, 0.75, and 1.0% led to respective increases of 48.17, 70.07, and 86.66% in the diagonal fracture force, as compared to the inclusion of steel fibers which resulted in increases of 18.24, 56.93, and 98.54% in diagonal fracture loads. The ideal ratio for enhancing the maximum shear capacity was found to be 0.75% of basalt. This specific percent resulted in the highest measured force out of the three percentages that were examined. The addition of basalt fibers at concentrations of 0.5, 0.75, and 1.0% resulted in respective improvements of 11.62, 30.08, and 28.69% in the ultimate shear capacities. During that period, steel fibers significantly enhanced the ultimate shear capacity, resulting in an increase of 19.83, 34.49, and 55.24% compared to specimens without fiber reinforcement. Regarding the second parameter of this investigation, a drop in the shear span ratio is linked to an augmentation in shear capacity and a reduction in mid-span deflection to varying extents for both the utilization of basalt and steel fibers.

Two-heads brick masonry walls strengthened by basalt and glass chopped fiber mortar: Effect of bed joints and coating reinforcements

It is urgent finding strengthening systems for masonry structures located in seismic areas. This paper studies the effect of chopped fibers embedded in a cementitious mortar to be used as a strengthening system for two-heads brick masonry panels subjected to diagonal compressive forces. The strengthening system provides the use of two types of chopped fibers dispersed in the mortar matrix, i.e. a glass fiber reinforced mortar (GFRM) and a basalt fiber reinforced mortar (BFRM). The retrofitting composite material is disposed in three different ways: (i) the reinforced mortar is placed within the mortar joints of masonry panel; (ii) the reinforced mortar is disposed on both external surfaces of the masonry panel, but the mortar joints are in plain mortar; (iii) the reinforced mortar is placed both within the mortar joints and as a double reinforcing system on the external surfaces of each masonry panel. Experimental results show that in all the three cases the use of fiber reinforced mortar enhances both the shear strength and the post-peak capacity of the two-heads brick masonry panel. The most suitable behavior is related to panels reinforced with mortar both within the joints and as external reinforcing system. From the comparison between GFRM and BFRM it is shown that the best performance is related to basalt fibers mortar, that is also the most sustainable one. Authors always recommend the use of dispersed fibers within the mortar matrix, as it stands as effective strengthening system for new and existing masonry structures, above all when they are located in areas characterized by seismic hazard.

Flexural behavior of RC beams with multiple parallelogram openings

On account of the detrimental effects of the post-drilling holes in hardened RC beams, designing the beams with transverse openings before construction is becoming more popular in the last decades. The contribution of the transverse openings to the overall economy and efficiency of construction by reducing the unusable dead space in the floor height is a rather significant motivation behind the vast number of studies on this topic. In search for the opening geometries and reinforcement schemes with the least negative effects on the beam behavior, the present study focused on the parallelogram (diamond) opening geometry, which is thought to facilitate the transmission of diagonal compression forces in the beam web thanks to the inclination of the posts. Within this scope, a total of 12 beams, including two reference beams without openings, were tested under four-point bending. Circular, square and parallelogram (45°−60°−75°) opening geometries were adopted and the test results were evaluated based on the opening geometry and the longitudinal reinforcement ratio. In order to avoid various shear failure modes of beams with openings, different special reinforcement schemes were employed around the web openings. Two different longitudinal reinforcement ratios were used to understand if pure flexural failure can be reached in RC beams with openings without being affected by different shear failure modes (beam- and frame-type diagonal tension and diagonal compression). The inclination angle of the posts between the openings in parallelogram opening geometry was found to be the most crucial parameter in the final beam failure and beam ductility. The use of diagonal cables surrounding the openings and connecting the posts and chords was established to be obligatory in square and parallelogram opening geometries to reach a ductile beam behavior without being affected by Vierendeel panel action and different shear failure modes.

Member control efficiency and shape control capability of a loaded cable dome

In this paper, the control efficiency of the members and shape control ability of a loaded adaptive cable dome consisting of 16 cables and 4 struts are investigated. The structure uses specially designed cables and electric telescopic struts integrated with an actuation control system, and all members of the structure are length-adjustable. Initially, an intelligent algorithm is employed to solve the structural shape optimization control model, thereby determining the optimal adjustment amounts. Subsequently, active adjustment and active control tests are conducted to evaluate the control efficiency of the members and the shape control capabilities of the cable dome. The results indicate that the ridge and diagonal cables exhibit the most effective control, followed by the upper and lower hoop cables, while the struts show the lowest control efficiency, primarily influencing the displacement of the joints at their two ends. Moreover, the cables' internal force control efficiency is 3–4 times higher than that of the struts. The ridge and diagonal cables' internal force and displacement control efficiency is about 1.5 times higher than that of the upper and lower hoop cables. The loaded test model exhibits the ability to restore the vertical coordinates of upper joints to their target coordinates, while reducing the internal forces of the components by at least 15 %, and the shape control capability of the structure can be enhanced by incorporating various types of active units. The measured values correlate well with the simulation results, validating the accuracy of the simulations.

A novel technique for repositioning facial soft tissues with barbed polydioxanone threads based on the main aging vector force of rejuvenation

Background: With the evolution of facial rejuvenation procedures, thread lifts have gained space among western patients who seek cosmetic improvement without undergo to surgeries. Absorbable wedge-shaped polydioxanone (PDO) sutures are currently available, and in mid-lower face and mandibular jowl lift, threads are most often implanted in a diagonal vector force from medial-inferior up to lateral-superior site, near the temple. Herein, the authors introduce a new technique based on this oblique sum of anti-aging vector force to reposition and anchorage facial soft tissues, aimed for natural youth rejuvenation. Objective: Describe a novel technique for counteracting the facial ptosis and laxity skin, as well as the duration of clinical lifting result and of skin quality improvement. Methods: More than 84 patients were underwent in this thread technique once. The outcomes were assessed objectively using serial photography and subjectively based on the patients’ spontaneous satisfaction through over these 4 years. Complications were also reported. Results: Most patients considered the results satisfactory. The incidence of complications was low, and most of them were minor and temporary. Conclusion: Wedge-shaped PDO thread repositioning and anchorage soft tissue is safe and effective method for rejuvenation.

Analytical Study on Lateral Strength of Multi-Span RC Frame with Masonry Infill

Abstract A simple and accurate analytical model for defining the lateral strength of the multi-span RC frame with masonry infill has been developed in this study. This model is developed due to the limitation of the current analytical model which only can be applied to the single-span RC frame. Meanwhile, the structure in the building also is in a multi-span frame and masonry infill greatly impacts the portal structure. In the existing building, this analytical method is needed to calculate the lateral strength of the RC frame. Besides, the analytical method was developed based on the lateral strength analysis method of a single-span RC frame in which the modeling of a multi-span RC frame with masonry infill along with uniform span spacing was applied. Furthermore, an equivalent diagonal strut with the same thickness and material as the masonry panels was used instead of masonry infill in the frame structure. The external column has diagonal compressive forces on the top or bottom of the column. On the other hand, diagonal compressive forces work at the top and the bottom of the column in the internal column. The lateral strength of the infill was determined based on the frame infill contact length. Furthermore, in order to obtain the lateral strength of the structure, the experimental study of a multi-span RC frame with masonry infill under cyclic load was also tested. Applying the analytical model has shown promising results even after being compared with the results of the experimental work.

Lateral load bearing characteristics of light gauge steel and lightweight concrete shear walls

In China, there is a new structural system named light gauge steel and lightweight concrete (LSLC) structure, which used lightweight concrete as structural material in composite way with cold-formed steel. Here, the shear walls are the main structural members for the LSLC structure, which are assembled with the light gauge steel lattice columns and horizontal braces, and filled with lightweight concrete. In this study, the LSLC shear walls are experimentally investigated to evaluate their failure mechanism and lateral load bearing capacity. For this purpose, several specimens with different shear span ratio are designed and tested under static cyclic loading. This paper presents the damage state and hysteresis loops of the specimens detailly. Then, the lateral load bearing characteristics of the LSLC shear walls are discussed according to the failure mechanism, such as shear and flexural failure. Finally, the calculation methods of lateral strength for the LSLC shear walls are proposed based on the diagonal strut mechanism and sectional force equilibrium.

ロングパイル人工芝における水平方向衝撃力の検討

The purpose of this study is to consider the two-dimensional impact force applied to the artificial turf with spike studs, especially focused on the horizontal impact force. The shock attenuation properties of sports surfaces are usually evaluated by reduction of maximum input force, for example, WA (World Athletics) adopted the EN14808 as the vertical force attenuation test. Otherwise, the horizontal impact attenuation has not been treated as the regulation of impact, although the most of impact in sports activities performed with diagonal impact force, including horizontal impact forces. In previous studies, we developed the two-dimensional impact test device with parallelogram structure which divide the vertical impact force to two-dimensional impact forces simultaneously. The impact test device can be set the various impact weights to generate the impact forces resembled to the ground reaction force in human running. And proposed the method for two-dimensional impact attenuation, named DFR (dynamic force reduction) because the horizontal impact forces were very dependent to the initial impact angle. Although the proposed method could evaluate the attenuation of various impact forces, there are some inappropriate cases especially in horizontal impact force attenuation. As the results, the horizontal impact force is very dependent to the impact angle and is independent to the vertical impact attenuation properties. Additionally, rubber chip as an infill material may cause increasing of horizontal impact force because it makes larger horizontal displacement in diagonal impact.

Comparative analysis of acoustic emissions produced in abrupt and non-abrupt fracture processes in reinforced concrete walls

The determination of the eventual abrupt fracture of a reinforced concrete structure is of fundamental importance to estimate and mitigate the possible damages caused by its failure; of particular importance are shear-type fractures since these usually lead to sudden failure of the structure. One way to determine the presence of shear-type micro-cracks is by parametric analysis of the acoustic emissions produced by the micro-cracks during their growth. In this analysis, a direct comparisson of the waveform allows a distinction to be made between tensile-type and shear-type events. In the present study, we performed a comparative analysis of fracture processes in two reinforced concrete walls. In one of the walls an out-of-plane force was applied leading to bending and a non-abrupt failure; in the other one diagonal forces were applied leading to an abrupt shear-type fracture. Acoustic emissions were detected throughout and we found that at least one of the parameters associated with the parametric analysis allows distinguishing between abrupt and non-abrupt failures. Our results suggest that parametric analysis of acoustic emissions could be a useful tool in the prediction of abrupt failures in reinforced concrete structures.

Origami-foldable tessellated Crystalline-Si solar cell module with metal textile-based stretchable connections

The increasing demand for photovoltaic (PV) electricity has resulted in wider usage for many applications. Current dominant PV electrical sources use crystalline silicon (c-Si) solar modules. These would provide greater potential as an energy source if they could be installed to any surface with a curvature, for example integration into buildings, and would perform better under omni-directional incident light, which is not considered in the design of current modules. In this study, we propose an origami-type foldable c-Si solar cell module by introducing a tessellated module design and textile-based woven metal connections to overcome the limitations of using c-Si solar cell modules on curved surfaces and under various light conditions. For the proposed module, two main concepts are introduced: a tessellation design for rigid folding and stretchable textile-based metal connections. The flexible crease pattern and interconnection allows the modules to be folded up to 180°, and a diagonal force on the metal textile can be induced on the inter-module connections using rotating wires. These features allow solar cell modules to cover an arbitrary surface without electrical degradation. Tessellating the module allows for maximum potential using the origami design when applied to both flat and curved surfaces. The origami-type foldable tessellated modules performed better than conventional modules. Their energy production under various angles of incident light is higher per day than that of flat modules, even during periods of lower intensity sunlight from a low solar altitude. These findings demonstrate a new approach to extend the usage of c-Si solar cells. • We introduced origami-foldable solar cell module for covering arbitrary surface. • The metal textile, the connector of the module, is stretchable and flexible. • Tessellated module with origami pattern allows rigid-folding without area loss. • The 64-cell module are successfully deformed as paper along the crease lines. • The energy production is higher per day than of flat modules.

Efficacy of prestressed SMA diagonal loops in seismic retrofitting of non-seismically detailed RC beam-column joints

In this study, a detailed experimental and numerical investigation is carried out to study the efficacy of prestressed SMA diagonal compression loops in seismic retrofitting of non-seismically detailed RC beam-column joints. Prestressed diagonal compression loops exert active confinement to the joint core which is found to perform better than the conventional passive confinement in terms of improving the shear strength, ductility, and energy dissipation capacity. In this study, active confinement of the joint core is achieved by applying in-plane diagonal compression forces using externally fastened prestressed NiTiNb shape memory alloy (SMA) diagonal loops. In the experimental part, two different techniques are investigated to prestress the SMA loops, which are: 1) rapid heat-activated prestressing technique utilizing the shape memory feature of SMAs; and 2) conventional prestressing of SMA loops by mechanical means. In the finite element analysis, a wide range of prestress values (post-tension force) is studied, keeping the basic arrangement same. The efficacy of the retrofitting technique is evaluated in terms of enhancement in strength, ductility, energy dissipation capacity, damage reduction in the specimens, and the ease of application. The results from this study suggest that depending on the applied confinement level, the retrofitting scheme can increase the ultimate strength in the range of 20–30% and the energy dissipation capacity in the range of 60–70% however, no significant enhancement in ductility of the retrofitted specimen may be achieved using this approach. The study also highlights the complexity involved in controlling the material behaviour of NiTiNb SMA wires and the risks associated with the application of SMAs in practical problems.

Absence of diagonal force constants in cubic Coulomb crystals.

The quasi-harmonic model proposes that a crystal can be modelled as atoms connected by springs. We demonstrate how this viewpoint can be misleading: a simple application of Gauss’s law shows that the ion–ion potential for a cubic Coulomb system can have no diagonal harmonic contribution and so cannot necessarily be modelled by springs. We investigate the repercussions of this observation by examining three illustrative regimes: the bare ionic, density tight-binding and density nearly-free electron models. For the bare ionic model, we demonstrate the zero elements in the force constants matrix and explain this phenomenon as a natural consequence of Poisson’s law. In the density tight-binding model, we confirm that the inclusion of localized electrons stabilizes all major crystal structures at harmonic order and we construct a phase diagram of preferred structures with respect to core and valence electron radii. In the density nearly-free electron model, we verify that the inclusion of delocalized electrons, in the form of a background jellium, is enough to counterbalance the diagonal force constants matrix from the ion–ion potential in all cases and we show that a first-order perturbation to the jellium does not have a destabilizing effect. We discuss our results in connection to Wigner crystals in condensed matter, Yukawa crystals in plasma physics, as well as the elemental solids.

Diagonal supercompact Radin forcing

Motivated by the goal of constructing a model in which there are no κ-Aronszajn trees for any regular κ>ℵ1, we produce a model with many singular cardinals where both the singular cardinals hypothesis and weak square fail.

Effects of mechanical perturbation gait training on gait and balance function in patients with stroke: A pre-post research study

Patients with stroke (PwS) demonstrate impaired gait and balance, and asymmetric gait, placing them at high risk of falls. We aimed to investigate the effects of a single training session that included mechanical external perturbation which resists forward movement of the paretic leg during its swing phase of walking on gait and balance in PwS. In a pre-post pilot study, gait asymmetry and balance function were assessed in 22 first-event chronic PwS (i.e., unilateral hemiparesis). PwS underwent tests during baseline and one week later, after participating in a single training session that resisted forward stepping during the swing phase of walking with a device secured around the patient's waist and connected diagonally to the patient’s foot by a tension cord. Ground reaction forces and center of pressure were sampled during treadmill gait to assess step length asymmetry. Performance-oriented mobility assessment (POMA), a two-minute walk test (2MWT), and the voluntary step execution test were also measured. We found no significant improvement in step length asymmetry. However, POMA scores, as well as voluntary step execution tests improved with a moderate effect size. It seems that applying diagonal resistance force to the swinging leg resulted in insufficient horizontal force. However, the improvement in the preparation phase, i.e., better weight-bearing abilities during the voluntary stepping, may be due to the compression force applied to the lower limb joints thus providing proprioceptive training. This suggests that proprioceptive training may improve gait performance in stroke patients in a very short training period.

Resonant three-dimensional nonlinear sloshing in a square base basin. Part 5. Three-dimensional non-parametric tank forcing

Assuming an inviscid incompressible liquid (with irrotational flows) partly filling a square base tank, which performs a small-amplitude sway/surge/pitch/roll periodic motion whose frequency is close to the lowest natural sloshing frequency, a nine-dimensional Narimanov–Moiseev-type (modal) system of ordinary differential equations with respect to the hydrodynamic generalised coordinates was derived in the Part 1 (Faltinsen et al., J. Fluid Mech., vol. 487, 2003, pp. 1–42). Constructing and analysing asymptotic periodic solutions of the system made it possible to classify steady-state resonant sloshing and its stability for the harmonic reciprocating (longitudinal, diagonal and oblique) forcing. The results were supported by experimental observations and measurements. The present paper finalises the case studies by considering the three-dimensional non-parametric (combined sway, pitch, surge, roll and yaw, but no heave) cyclic tank motions. It becomes possible after establishing an asymptotic equivalence of the associated periodic solutions of the modal system to those for a suitable horizontal translatory elliptic forcing so that, as a consequence, resonant steady-state waves and their stability can be considered versus angular position, semi-axis ratio and direction (counter- or clockwise) of the equivalent orbits. The circular orbit causes stable swirling waves (co-directed with the orbit) but may also excite stable nearly standing waves. The orbit direction does not affect the response curves for wall-symmetric (canonic) and diagonal orbit positions. This is not true for the oblique-type elliptic forcing. When the semi-axis ratio changes from 0 to 1, the response curves exhibit astonishing metamorphoses significantly influencing the frequency ranges of stable nearly standing/swirling waves and ‘irregular’ sloshing. For the experimental input data by Ikeda et al. (J. Fluid Mech., vol. 700, 2012, pp. 304–328), the counter-directed swirling disappears as but the frequency range of irregular waves vanishes for .

The Effect of Fastener Type (Clamex P14 and Tenso P14) and Adhesive Type on Compression and Tension Performance

In this study, the effects of different fasteners (Clamex P14 and Tenso P14) for medium density fiberboard (MDFLamM) surfaced with synthetic resin sheet wood-based materials as well as several adhesives (PVAc-D4) and PU-D4) on diagonal tension and compression forces, were analysed. In the study, melamine coated medium density fiberboard (MDF-Lam) was used as wood-based material, Clamex P14 and Tenso P14 were used as fasteners and polyvinylacetate (PVAc-D4) and polyurethane (PU-D4) glues were used as adhesive agents. The diagonal tension and compression force tests were applied on 120 pieces of test samples prepared in this respect based on the principles of ASTM D 1037. As a result, The diagonal compression and tensile forces values were found in the highest Clamex P14 fastener and polyvinylacetate adhesive bond (PVAc-D4), the lowest was in the joint with Tenso P14 fastener without any adhesive agent. For L type corner-joints, it is suggested to use Clamex P14 as a fastener and polyvinylacetate adhesive (PVAc-D4) as the type of the adhesive agent.

The Moving-Grid Effect in the Harmonic Vibrational Frequency Calculations with Numeric Atom-Centered Orbitals.

When using atom-centered integration grids, the portion of the grid that belongs to a certain atom also moves when this atom is displaced. In the paper, we investigate the moving-grid effect in the calculation of the harmonic vibrational frequencies when using all-electron full-potential numeric atomic-centered orbitals as the basis set. We find that, unlike the first-order derivative (i.e., forces), the moving-grid effect plays an essential role for the second-order derivatives (i.e., vibrational frequencies). Further analysis reveals that the predominantly diagonal force constant terms are affected, which can be bypassed efficiently by invoking translational symmetry. Our approaches have been demonstrated in both finite (molecules) and extended (periodic) systems.

An innovative method for calculating diagonal lashing force of cargo on railway wagons in a curve alignment

Due to super elevation and centrifugal force, close attention is needed to lateral stability of cargo when the train negotiates curves. To guarantee the security of cargo on wagons, proper blocking, bracing and lashing are essential. In this study, we implement a cargo–wagon–rail coupling model that adopts diagonal lashing to restrain cargo movement. A preliminary dynamic simulation analysis demonstrates that the selected cargo tilts when the wagon negotiates curves. The quasi-static analysis reveals the cargo force condition and the key role of lashing stiffness. Coupling models are endowed with various lashing stiffness values. The curving performance of each model is evaluated considering different running conditions. The results indicate that increasing lashing stiffness reduces lateral cargo vibration and increases lashing tension force until the stable state. The cargo movement in this study is proved to have no significant effect on the wheel–rail interaction. Based on simulation results, this paper determines the diagonal lashing. It is demonstrated that the use of dynamic simulation to calculate the diagonal lashing force will improve cargo stability and avoid unnecessary expenditure on load restraint assemblies. Finally, it is proved that the promotion of pre-tension force is not necessary for diagonal lashings.

The subcompleteness of diagonal Prikry forcing

Let $$D$$ be an infinite discrete set of measurable cardinals. It is shown that generalized Prikry forcing to add a countable sequence to each cardinal in $$D$$ is subcomplete. To do this it is shown that a simplified version of generalized Prikry forcing which adds a point below each cardinal in $$D$$, called generalized diagonal Prikry forcing, is subcomplete. Moreover, the generalized diagonal Prikry forcing associated to $$D$$ is subcomplete above $$\mu $$, where $$\mu $$ is any regular cardinal below the first limit point of $$D$$.