Maximum Bending Research Articles

Evaluation of Boron as a Feed Additive to Improve Musculoskeletal Health of Hy-Line W-36 Pullets

Boron supplementation may improve the musculoskeletal health of pullets before entering the lay phase. This study aimed to evaluate the effects of different boron amounts on the performance, muscle deposition, tibia cross-sectional area (CSA) and mineral density (BMD), ash percent, breaking strength, and bone mineralization (bone-specific alkaline phosphatase [BALP] and pro-collagen type 1 n-terminal propeptide [P1NP]) of a white-feathered strain of pullets. A total of 528 Hy-Line W-36 pullets were distributed across 24 pens and fed basal diets containing varying amounts of boron (C: 0 mg/kg; L: 50 mg/kg; M: 100 mg/kg; H: 150 mg/kg) for 17 weeks. Performance parameters (body weight, average daily weight gain/bird, and average daily feed intake/bird) were measured at weeks 4, 7, 10, 13, and 16, while all other measures were taken at 11 and 17 weeks of age. Performance was not impacted by boron supplementation. Pectoralis major weights were higher in H pullets at 11 weeks of age, and we also observed higher pectoralis major, minor, and leg muscle weights in H pullets at 17 weeks of age. Pullets fed the H diet had larger cortical CSA than the other treatment groups at 11 weeks of age. At 17 weeks of age, both the H and M groups had larger cortical CSA than the L and C groups, but the M group had slightly smaller cortical CSA. Pullets fed the H diet had higher BMD values than the other treatment groups at 11 weeks of age. At 17 weeks of age, pullets fed the H diet had the highest total BMD values compared to the other treatment groups, and cortical BMD increased with increasing boron inclusion. Pullets fed the H diet had the highest tibia ash percentages and concentrations of BALP and P1NP. Pullets fed the M and H diets had greater failure load and maximum bending moment than pullets fed the L or C diet at 11 weeks of age, with H pullets having greater stiffness values than other groups. At 17 weeks of age, pullets fed the H diet had greater failure load and maximum bending moment compared to all other treatment groups. Our results suggest that providing boron within the diet at 150 mg/kg can improve the musculoskeletal characteristics of Hy-Line W-36 pullets up to 17 weeks of age, without impacting performance parameters.

Investigation of Concrete Damage on a Prefabricated Steel Spring Floating Slab Track by Finite Element Modelling

To investigate the concrete damage of prefabricated steel spring floating slab tracks (SSFST), a three-slab prefabricated SSFST system was established using the ABAQUS finite element software. Full trainload conditions and fatigue load conditions of a train passage were successively applied to the system. Plastic damage and fatigue damage of the floating slab were simulated based on concrete damage plasticity theory and model code, respectively. For comparison, a simulation of the fatigue experiment was conducted. Parametric analyses of the concrete strength and isolator stiffness were also performed. The results show that the maximum positive and negative bending moments of the floating slab throughout the loading stage are close in value. The positive bending moment causes stress concentration on the top slab surface which leads to plastic damage and low-cycle fatigue damage, while the negative bending moment causes middle-level elastic tensile stress on the bottom slab surface which leads to high-cycle fatigue damage. Under experimental conditions, damage on the bottom surface is much more severe, while the upper part is undamaged. Improving the concrete strength can reduce both kinds of damage, while increasing the isolator stiffness can only mitigate the high-cycle fatigue damage. Accordingly, recommendations are provided for improving fatigue experiments and structural design of prefabricated floating slabs.This study can inform the design and maintenance of the prefabricated SSFST system, ultimately enhancing their safety and longevity.

Development of conformable cryogenic valve seats for resilience to foreign object debris

Cryogenic valve sealing technology is notoriously more challenging than traditional fluids due to the combination of small atoms and molecules with extreme temperature and pressure profiles. Recently, flexible polymeric films folded into origami demonstrated considerable resilience to mechanical failure in the cryogenic extreme. Fluorinated polymers such as Polytetrafluoroethylene (PTFE) are observed to mechanically flex and not plastically deform in cryogenic conditions. This paper explores a new cryogenic valve sealing paradigm which uses multiple conformable polymer layers to provide constant seat mating surface area at cryogenic conditions. Stacking these thin discs in series with a spacer allows maximum bend around the seat while creating multiple sealing surfaces. Experimental measurements of leakage rates with and without the presence of Foreign Object Debris (FOD) are compared with traditional re-closable pressure relief valves. Conformable cryogenic valve seats have the potential to be more repeatable, decrease leakage rates from differing coefficients of thermal expansion, hysteresis, and FOD when compared to traditional market valves.

Ultrashort pulse laser welding of alumina ceramic and titanium

The direct welding of alumina ceramic and titanium using ultrashort pulse laser was successfully achieved for the first time. Benefitting from the extremely high peak power of ultrashort pulse laser, ceramics can be melted at a very low laser power. The emerging welding method was conducted at room-temperature without the need for preheating. Within the joint, a combination of Ti and Al elements was observed. A newly formed TiO2 phase was identified at the Al2O3/welding seam interface. Under the optimal welding parameters (welding speed: 0.8mm/s, laser power: 19.52W), the joint achieved a maximum four-point bending strength of approximately 134.9MPa. This study proposed a new methodology for butt welding of ceramics and metals and shows a much higher efficiency than the commonly used ceramic-metal joining approaches such as brazing and diffusion bonding.

Numerical simulation of bending characteristics of geosynthetic encased stone column

A numerical model of the cantilever bending structure of a geosynthetic encased stone column (GESC) of length 3 m and diameter 0.3 m was established using Z-Soil. The aim was to analyze the stress distribution and bending characteristics of the GESC under a bending load and to investigate the impact of encasement strength, encasement stiffness, gravel friction angle, and diameter on the bending characteristics of the GESC. The maximum bending moment of the GESC under bending conditions occurs at the anchored end. The dividing line of tensile and compressive stresses on the gravel in the anchored end section after bending failure appears at a radius of 0.5 of the column above the section centerline. The geosynthetic sleeve exhibits good resistance to tensile stress. The dividing line between the tensile and compressive stresses is located at the centerline of the section. The mechanical properties of the encasements and gravel has a significant impact on bending characteristics of the GESC. Increasing the strength of the encasement and friction angle of the gravel may significantly improve the bending capacity of the GESC, whereas an increase in the stiffness of encasement and diameter of the column decreases the bending deformation of the GESC.

Numerical analysis of failure mechanism and stability of reinforced embankment with DCM soft soil composite foundation

The deep cement mixing (DCM) method has been widely used in offshore geotechnical engineering. At present, the reinforcement form of pile has been researched widely, but there is a lack of understanding of the failure mode of DCM pile composite foundation reinforcement for bank slopes. In this paper, a series of unconfined compression tests was conducted to obtain necessary numerical analysis parameters. A series of study on the failure mechanism and stability control of DCM pile composite foundation reinforcement bank slope has been conducted through numerical analysis. The results of numerical analysis indicate that under different reinforcement conditions, there exists an optimal reinforcement depth, and the safety coefficient will gradually stabilize at 1.45; The bending moment of the piles under the bank slope the bending moment of the pile body under the road surface Under different overloads. The maximum bending moment of the pile body is located near one-third of the pile body, and the maximum bending moment of the pile body is located between the shoulder and foot of the slope.

Experimental study on the stability of dike reinforced by steel sheet pile under storm surge

Over recent decades, upgrading dikes that defend against storm surges increasing in both intensity and frequency resulting from global warming, face challenges such as environmental impact and susceptibility to brittle failure. To address this issue, the steel sheet pile can be employed to improve the dike stability due to its resilience in withstanding substantial deformation. To investigate the reinforcement mechanism of the steel sheet pile, this study conducted three wave flume tests including the dike without configuration, the dike with single sheet pile, and the dike with double sheet pile. The dike stability and pile bending moment were analyzed based on the monitoring data. The experimental results showed that the single pile significantly improved the dike stability by reducing the seepage. The maximum bending moment for the single sheet pile occurred at approximately 1/3 of the pile depth, primarily due to its proximity to the wave impact area on the dike. The double pile further enhanced the dike stability primarily through the reduction of wave scour. The maximum bending moment for the double pile occurred at a lower position (2/3 of the pile depth) and was smaller due to the external force distribution and tie rod limitation.

Influence of the main parameters of laser impact forming on the bending of plates

Laser impact forming (LIF), in which a shock wave deforms a thin plate, is studied. The LIF process is simulated using the finite element method. It is established that the maximum bending curvature of the plate can be obtained by adjusting the overlap coefficient of laser spots, the number of repeated laser pulses, and the power density of the laser beam. Keywords:laser impact forming, finite element method, residual stresses, bending, plate curvature sakhvadze@mail.ru

Evaluation of low-temperature anti-cracking and slow-release performance of salt-storage AC-13

Asphalt mixture AC-13 was prepared using homemade salt storage additives to replace an equal volume of mineral powder. The study focused on the low-temperature anti-cracking and slow-release properties of the AC-13. The results indicate that the incorporation of salt storage additives gradually reduces the “bending tensile strength (RB )” and “maximum bending strain (εB )” of the AC-13. The εB of the salt storage bituminous mixture with a replacement rate of 100% is reduced by more than 10%, but it still meets the specifications. The analysis of slow-release performance reveals that the dissolution rate of snowmelt salt in the salt storage AC-13 is uniform, with a stable precipitation amount. The slow-release effect is good and long-lasting.

Mechanical responses of shallowly buried pipelines to adjacent deep excavations considering heavy rainfall influence

Climate change has resulted in a high global incidence of heavy rainfall, severely damaging the urban infrastructure. The analytical method used to predict the mechanical response of pipelines under the influence of rainfall influence could serve as a valuable design basis in the preliminary stage. This study developed an analytical solution based on the stratified Green-Ampt model and displacement-controlled two-stage method. The first stage evaluates the greenfield soil displacement at pipeline elevation by employing the Mindlin solution and considering the superposed effects of excavation (unloading) and rainfall infiltration. The second stage predicts the mechanical responses of the pipeline by simplifying the pipeline–soil interaction into a continuous Euler–Bernoulli beam resting on a Winkler foundation model. The analytical solution was calculated using the finite difference method and verified against a published study. Finally, parametric studies were conducted to investigate the rainfall– excavation–pipeline interaction, including the rainfall intensity and duration, maximum lateral wall deflection, and pipeline location. The results showed that a 48-8-mm/h rainfall increased the maximum displacement and maximum bending moment of the pipeline by 6.54% and 7.93%, respectively. The prediction results provide practical guidance for designing deep excavations adjacent to pipelines buried under heavy rainfall conditions.

An optimized complementary design based on trilayer graphene oxide and clay composites for three stimuli responsive actuator

To promote the practical development of actuators, it is urgent to develop new multi-responsive actuators. Asymmetric bilayer actuators were reported to be dual-responsive, which can be driven by humidity and light. However, it remains a great challenge to develop rational designs for fabricating high-performance multi-responsive actuators. Here, we propose an optimized complementary design for three stimuli responsive actuators that can respond to multiple organic vapors, humidity, and light. The actuator is designed to achieve complementarity through a trilayer construction with graphene oxide (GO) in the middle layer, and with montmorillonite (MMT) and biaxially-oriented polypropylene (BOPP) on both sides, utilizing their hygroscopicity, organic vapor absorption, light absorption and thermal expansion capabilities. The maximum bending curvatures of the actuator under humidity, organic vapor and light stimulation conditions are 6.60 cm-1, 4.12 cm-1 and 2.59 cm-1 respectively, which are better than that of mixed GO-MMT/BOPP bilayer actuators. To reveal the kinetics of actuation, the actuation speed, temperature and mass during the deformation process are studied, which behave in sync with the bending curvature. Finally, a wireless intelligent claw and an organic-vapor leakage alarm are demonstrated based on these actuators. This study will provide an enlightening reference for multi-responsive actuators and promote their practical development.

Comparative Study of G+6 Irregular Multistoryed Building of Different Shape of Diaphragm

Abstract: This study investigates the effectiveness of incorporating openings in the roof of re-entrant corner plan irregular buildings at different locations under earthquake loads. Five models with varying degrees of diaphragm discontinuity were analysed using STAAD Pro software. Node displacement, storey shear in X and Z directions, stress values, and maximum bending moment were evaluated to assess structural performance. Results indicate that models with higher diaphragm discontinuity exhibit increased node displacements, storey shear, and stress levels. Model M3, with 17% diaphragm discontinuity, consistently demonstrates superior performance in terms of lower displacements and stress values compared to other models. However, final model selection should consider specific project requirements and design considerations.

Structural Design Analysis Torque Links of Nose Landing Gear on Light Aircraft

Torque links are components of Nose Landing Gear on the designed lightweight aircraft, that connect between the inner and outer cylinders of an oleo-pneumatic shock strut. They prevent torsion or twisting between those components and vibrations at retractable nose landing gear, the safety of these components is very important, especially when landing aircraft. This paper studies the stress and deformation contours of the torque link design with variations of hole geometry to get the optimal design, with the lightest possible weight but still reliable and safe. The upper torque link is modeled as a simply supported beam with a moment on one end derived from impact force when landing. Maximum bending stresses occur in areas near holes and the connection part of the torque link. This analysis with a tetra mesh by changing the hole position and geometry. The final torque link design results in a weight reduction of up to 23.75% with a maximum stress is 157.4 MPa and displacement is 0.0166 mm. Torque link design optimization results are then modally analyzed, and four natural frequencies and the mode shape are done. The natural frequency of vibration of different mode shapes obtained ranges from 4.2259 kHz to 6.1319 kHz, and this is still below the limit of 0.1 kHz (around 6,000 rpm engine). Finally, the optimal design torque links were obtained, safe from static and dynamic loads with a Factor of Safety 1.78 (>1.5) according to the FAR-23 standard.

Enhancing flexibility in BaTiO3:Sm3+ freestanding nanofiber membranes through Poisson's ratio design

In recent years, flexible functional materials have attracted increasing interest, but there is a lack of designing mechanisms of flexibility design with superstructures. In traditional engineering mechanics, the maximum bending strain (MBS) was considered universal for describing the bendable properties of a given material, leading to the universal designing method of lowering the dimension such as thin membranes designed flexible functional materials. In this work, the MBS was found only applicable for materials with uniformly distributed Poisson's ratio, while the MBS increases with the thickness of the given material in case there is a variation Poisson's ratio in different areas. This means the MBS can be enhanced by certain Poisson's ratio design in the future to achieve better flexibility of thick materials. Here, the macroscopic freestanding inorganic functional BaTiO3:Sm3+ (BTO:S) nanofiber membranes, which have a nonconstant Poisson's ratio response on stress/strain for creating nonuniformly distributed Poisson's ratio, were proven applicable for designing larger MBS and lower Young's modulus for flexible functional materials.

Unidirectional horizontal cyclic behaviors of the monopile-wheel composite foundation in sand

The monopile-wheel composite foundation is an innovative type of offshore wind turbine (OWT) foundation with good bearing capacity. The foundation is subjected to cyclic loads from wind, waves, and tides, so it is necessary to study its horizontal cyclic characteristics. By introducing cyclic degradation constitutive and Rayleigh damping parameters, numerical models are generated and validated by comparing with laboratory experiment results. The laws of horizontal accumulated displacement of the composite foundation are then explored through changes in the cycle amplitude, number, wheel diameter, height of loading point and pre-vertical load. The main findings are that the composite foundation is more likely to reach a stable displacement under constant amplitude cyclic loading compared to that of monopile. Under transient dynamic response (74 % of the horizontal ultimate bearing capacity), accumulated displacement will increase rapidly regardless of the foundation form. The composite foundation has smaller hysteresis loop area and slower accumulation rate of bending moment. The soil pressure weakening of the monopile mainly occurs in front of the pile, while that of the composite foundation mainly occurs under the wheel. After cyclic loading, the V–H envelopes for the composite foundation contract unevenly inwards. Above these, prediction methods for the cumulative displacement, maximum bending moment and V–H envelopes for composite foundation considering cyclic degradation are proposed.

Effect of sintering temperature and silicone resin content on in-situ formed SiC nanowire reinforced ceramic shells

The silicone resin was used to modify ceramic shells for investment casting. SiC nanowires were in-situ formed by the carbothermal reduction method. The pyrolysis of silicone resin and the formation mechanism of SiC nanowires were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the shells had the maximum sintering bending strength of 7.35 MPa when the silicone resin content and the sintering temperature were 20 wt% and 1300 °C, respectively. The phase of β-cristobalite during the transformation from amorphous SiOC to fused SiO2 after the pyrolysis of silicone resin impacted the bending strength. In addition, the iron oxide in corundum sand was used as the catalyst in the VLS mechanism to form the ball-stick-shaped SiC nanowires at 1000 °C–1100 °C. However, the necklace-like and rod-like SiC nanowires were formed at 1200 °C–1300 °C in the VS mechanism, which replaced the VLS mechanism.

Damage and fracture investigation of self-compacting concrete in the filling layer of CRTS-III using three-point bending tests

Literature about filling layer self-compacting concrete (FLSCC) has indicated that FLSCC plays a crucial role in its application to Chinese railway track system III (CRTS-III). It is apparent that the damage characteristics of FLSCC have not been clearly investigated, as the actual working conditions are not considered enough. There exists a remaining gap about the mechanical properties and fracture behaviors of FLSCC under bending loads. In order to fill this gap, in this study, three-point bending (TPB) tests on the FLSCC beams with precast notches were performed based on the real bending situation of FLSCC in CRTS-III. Acoustic emission (AE), strain gauges and a digital camera were utilized to monitor the fresh evolutionary laws of micro- and macro-cracks as well as the corresponding damage morphology. The study presents that the monitored load-crack mouth opening displacement (P-CMPD) curves, load-strain (P-ε) curves and AE activity curves all exhibited similar distributions, including four stages with increasing bending loads. In term of the AE activities, the first apparent crack in the interior and warning point of failure can be detected by analyzing the captured AE activities of the FLSCC beams. In addition, the dominant failure mode of the specimens was determined as tensile cracks according to the rising angle-average frequency (RA-AF) criterion for potential FLSCC application in terms of the limiting ratios. This failure mode indicates that under pure bending loads, the mid-span section is subjected to the maximum bending moment, and the specimen experiences tensile damage. Therefore, for future practical application, the structural health state of FLSCC in CRTS-III could be nondestructively real-time monitored by the AE technique. Meanwhile, the calculated fracture parameters of the FLSCC specimen can reflect the cracks stability of the specimen. This study can also present experimental and theoretical references for further studies on FLSCC in CRTS-Ⅲ under other types of loads.

Influence of Ti addition on the microstructure and comprehensive properties of Mo–Cu alloy

To enhance the overall performance of Mo–Cu alloy, Ti was added to Mo–Cu alloy to improve the bonding strength of Mo/Cu interface and generate solid solution strengthening effect. The outstanding performances of Mo–Cu–Ti alloys were achieved by infiltrating Cu–Ti alloy with different compositions into the Mo skeleton. Compared to the incoherent interface of Mo/Cu in Mo–Cu alloy, the addition of Ti transformed its interface to the coherent interface of Mo–Ti/Cu–Ti. All Mo–Cu–Ti alloy blocks had higher relative densities (97.4%∼98.5%) to guarantee the excellent comprehensive performances. What's more, the existences of Mo–Ti and Cu–Ti solid solutions assured the alloy possessed relatively high mechanical strength. The introduction of Ti purified the grain boundary by absorbing oxygen to generate TiO2 which hindered the growth of Mo–Ti grains. As increasing Ti amount from 0 wt% to 4.62 wt%, the Mo–Ti (or Mo) grain size reduced from 5 μm to 4.1 μm. Notably, Mo–Cu alloy block with the addition of 2.30 wt% Ti possessed the highest tensile strength of 562 MPa. Additionally, since the finer grain size of Mo–Ti alloy, this sample also owned the maximum micro-hardness and bending strength of 268 HV and 1730 MPa, respectively. Nevertheless, the presences of Cu–Ti solid solution and TiO2 also destroyed the electrical conductivities of the samples to some extent.

Investigation on the flexural–tensile behaviour of CFRP tendon composite anchorage system

The cable at the anchorage end is in a bending–tension condition in service due to the variable loads. A new composite anchorage system was proposed to study the flexural–tensile behaviour of the anchorage system with CFRP tendon. Four groups of single-tendon composite anchorage and three groups of five-tendon composite anchorage with bend restrictor were tested. Besides, one group of five-tendon composite anchorage without bend restrictor was tested as a control group. The effects of the bending angle, inner cone angle of the steel barrel and pre-tension force on the flexural–tensile behaviour of the anchorage system were investigated. The internal force state of the tendon inducing different failure modes was analysed. A finite element method was used to analyse the failure mechanism of the anchorage system under the bending–tension condition. Moreover, the flexural–tensile behaviours of the anchorage systems with different elastic moduli of the bonding medium were compared. Results showed that the efficiency coefficients of the composite anchorage with multi-tendon exceeded 0.9 when the end bending angle was less than 4.2°. The setting of the bending restrictor improves the flexural–tensile bearing capacity of the anchorage system and increases the maximum allowable bending angle. A larger bending angle will lead to a faster increase in the transverse shear stress at the loading end. Furthermore, increasing the pre-tension force can prompt the cooperation ability of the tendons and reduce the ultimate slips, thus improving the ultimate load-bearing capacity of the anchorage. The increase in the elastic modulus remarkably reduces the slip of the tendon, but increases the shear stress at the loading end under the bending–tension condition.

Experimental study on the progressive collapse mechanism of excavations retained by tied-back retaining systems

Progressive collapses of tied-back excavations caused by the failure of some anchors often occur. However, the mechanism through which partial failure evolves to global failure and how the local failure rate influences progressive collapse has not been investigated. In this study, anchor failure experiments involving tied-back excavation were designed to explore the load transfer path and rule in the case of partial anchor failure. The results showed that, anchor failure leads to an increase in the axial force on adjacent anchors, an increase in the maximum bending moment of capping beams, and easy damage in capping beams due to structural reinforcement. The lower the anchor elevation is, the greater the excavation depth, and the greater the load transfer coefficient (axial force). The failure rate of anchors has an effect on the stress redistribution of the structure and the soil arching effect. In multi-row anchored pile retaining excavations, more rows of anchor failure could trigger the remaining anchors failure because the load transfer coefficient (axial force) is greater for these anchors, which leads to large-scale excavation collapse.