Bending Moment Responses Research Articles

Longitudinal and circumferential bending moment responses of dislocated concrete pipes rehabilitated with CIPP liners under traffic loads

Longitudinal and circumferential bending moment responses of dislocated concrete pipes rehabilitated with CIPP liners under traffic loads

3D numerical response of different pipe pile under combined loadings condition embedded in loose sand

ABSTRACT One significant phenomenon not adequately considered in the present design recommendations is pipe pile plugging. Understanding its mechanism is essential for designing new structures. A series of numerical simulations were established to investigate the bending moment, end bearing, and lateral displacement responses of open-ended pipe piles with and without a soil plug and closed-ended pipe piles. After the model has been verified through experimental work, many parameters were performed such as friction angles, pile length, and pile head. It was concluded that for all pile types, there is a significant decrease in the end bearing capacity with the increase of friction angle. Similarly, the bending moment decreases as the friction angle increases. In addition, the maximum bending moment gradually increases with the increases of pile length. Finally, the maximum lateral displacement decreases linearly with the friction angle for different conditions of soil inside the pile, pile lengths, and e/L.

Real-time prediction of structural responses in deep-water jacket platforms using Ada-STLNet: A comprehensive analysis with prototype monitoring data

Real-time prediction of structural responses in deep-water jacket platforms using Ada-STLNet: A comprehensive analysis with prototype monitoring data

Seismic response study of multi-span continuous beam bridges near faults considering permanent displacement attenuation effects

Seismic response study of multi-span continuous beam bridges near faults considering permanent displacement attenuation effects

Lateral impact performance of pitting corroded CFST columns for offshore applications

Lateral impact performance of pitting corroded CFST columns for offshore applications

Shaking table test for near-valley underground station: Influence of diaphragm walls

Shaking table test for near-valley underground station: Influence of diaphragm walls

Finite element analysis of locally strengthened stainless-steel tube under lateral impact loading

Finite element analysis of locally strengthened stainless-steel tube under lateral impact loading

Influence of local scour on the dynamic response of bridges under barge collisions

Influence of local scour on the dynamic response of bridges under barge collisions

Virtual sensing via Gaussian Process for bending moment response prediction of an offshore wind turbine using SCADA data

Virtual sensing via Gaussian Process for bending moment response prediction of an offshore wind turbine using SCADA data

A new improved fractional Tikhonov regularization method for moving force identification

A new improved fractional Tikhonov regularization method for moving force identification

Seismic Response Mitigation of Steel‐Concrete Hybrid Wind Turbine Tower by Using Isolation Bearings and Distributed Tuned Mass Dampers

The onshore wind turbines are gradually developing with the aim of large single‐unit capacity, large impeller diameter, and higher towers. The steel–concrete hybrid tubular tower structure is the mainstream structure of high‐hub towers, whose lower part is a concrete tower tube and the upper part a steel tower tube. Also, there is no doubt that more and more wind turbines will work in harsh environments and seismic hazard zones. Based on the abovementioned two points, it is necessary to mitigate the dynamic responses of onshore wind turbines to ensure the safety of these structures. This paper studied the base‐isolated method, story‐isolation method, and three types of tuned mass dampers damping method: single tuned mass dampers (STMDs), multiple tuned mass dampers (MTMDs), and distributed‐tuned mass dampers (D‐MTMDs), to explore the response characteristics of the steel–concrete hybrid tubular tower under seismic loads. The results show that the base‐isolated structure can greatly reduce the bending moment and shear response of the upper steel tower tube, while the story‐isolated structure has a very good effect on reducing the structural displacement response. In the three tuned mass dampers damping method, D‐MTMDs have stable and effective control capacity, compared with STMD and MTMDs.

Shaking table test of prestressed high-strength concrete pipe piles reinforced with non-prestressed steel reinforcement

Shaking table test of prestressed high-strength concrete pipe piles reinforced with non-prestressed steel reinforcement

Effect of wingtip bending morphing on gust-induced aerodynamics based on fluid-structure interaction method

This paper investigates the effect of wingtip bending morphing on gust-induced aerodynamics based on the fluid–structure interaction (FSI) method at Re = 40 000. First, an explicit spatiotemporal numerical model for a wingtip bending morphing on a wing with a semi-aspect ratio of 4 is deduced, considering geometrical nonlinearity under large morphing amplitude. A modal-based FSI framework is developed to consider the elastic deformation, active wingtip morphing, and gust. The shear-stress transport-γ model is introduced. The above FSI method is validated by gust response experimental results. The mitigation effects of active bending morphing on gust-induced aerodynamics at different phase offset, gust ratios (GR), and flare angles are investigated. Under GR = 0.2 and flare angle = 0, wingtip bending morphing achieves the best mitigation effect when the phase offset is π/2. As GR increases to 0.4, the optimum phase offset shifts to π/3 and the alleviation rate decreases. The mitigation rate increases with the flare angle. Under GR = 0.4 and flare angle = 30°, the optimum phase offset is π/6, in which case the lift response is reduced by 37%, and wing root bending moment response is reduced by 73% relative to the baseline case. The flow field and vortex evolution result infers that the wingtip bending morphing decreases the spanwise width of the leading-edge vortex and reduces the area of low-pressure zones on the suction side, thereby mitigating gust-induced aerodynamics. The results indicate that active wingtip bending morphing has great potential for gust load alleviation for future aircraft.

Theoretical study on the bending collapse of multi-cell thin-walled rectangular beams

Theoretical study on the bending collapse of multi-cell thin-walled rectangular beams

Bending moment response of batter piles in clay under spudcan-pile interaction

Bending moment response of batter piles in clay under spudcan-pile interaction

Experimental Analysis of the Influence of Heat Treatments on the Flexibility of NiTi Alloy for Endodontic Instruments Manufacturing.

The flexibility of NiTi based endodontic files is improved by heat treatment, leading to lower risk of failure, ledges, and canal transportation during the preparation of curved root canals. The aim of this study is to investigate and clearly highlight the influence of every parameter of heat treatment on the flexibility of NiTi wires and thus of endodontic instruments. A full factorial Design of Experiment (DoE) and a designed bending-torsion bench following the ISO 3630-1 standard were used for this investigation. Temperature, holding time, and cooling method were selected as contributing factors, while maximum bending moment, hysteresis size, and stiffness during martensitic transformation were selected as outputs. Regression analysis was performed to estimate the relationship between contributing and output variables to assess how the experimentation fits with the model. The experimental results showed that wires heated at 425 °C for 30 min are more flexible. Moreover, heat treatment temperature is the most critical factor influencing the flexibility and hysteresis size of the NiTi wire followed by the holding time, while the cooling method has a negligible effect. The regression analysis showed that the model is effective at predicting the relationship between contributing factors, bending moment response, and hysteresis size.

Deformation-based pushover analysis method for transverse seismic assessment of inverted Y-shaped pylons in kilometer-span cable-stayed bridges: Formulation and application to a case study

Deformation-based pushover analysis method for transverse seismic assessment of inverted Y-shaped pylons in kilometer-span cable-stayed bridges: Formulation and application to a case study

Seismic response and nonlinear characteristics of pile‐soil springs in structures supported by pile group in granular soil on sloping bedrock

AbstractIn places prone to earthquakes, piles need to be designed to resist seismic damage. However, the characteristics of the soil significantly impact the seismic resistance of piles. Accordingly, in this study, shaking table tests and three‐dimensional finite element analyses were conducted to investigate the seismic response and nonlinear characteristics of pile‐soil springs of a structure supported by a pile group in granular soil on a sloping bedrock. The analytical experiments and simulation were conducted on a group of nine piles arranged in the shape of a square. The results showed that the constraint condition at the pile tip influenced the bending moment response of piles during large input motion, such as that observed during earthquakes. Furthermore, the pile location, direction of pile displacement, and depth was found to affect the influence of the sloping bedrock on the pile soil springs.

Effects of axial loading on dynamic response of laterally loaded single piles in liquefiable layered soil of Kolkata city considering nonlinearity of soil

In the present study, an advanced nonlinear finite-element based 3D numerical study has been carried out to investigate the effects of axial loading on dynamic response of soil-pile system in liquefiable layered soil deposits of Kolkata city. An advanced soil constitutive law based on multi-yield surface plasticity model implemented in fully-coupled u-p formulation is adopted for soil-fluid interaction and pore water pressure development reasonably. The present model is validated with the past experimental results. Then, a detailed systematic parametric study is performed for numerical simulation of pile failures in layered soil deposit under axial loading by taking into account various soil conditions, pile and ground motion parameters. It is seen that the depth of liquefaction (DL) is decreased from 11.5 to 1.5 m adjacent to the pile when the axial load on pile increases from 0 to 1327 kN. Parametric studies also reveal that the bending moment response of pile under axial loading can be higher in non-liquefiable condition, with reference to the liquefiable condition. The peak lateral displacement decreases by 83.2% in non-liquefiable condition and 60.71% in liquefiable condition due to decrease of axial load from 1327 to 0 kN. Also, peak bending moment developed in the pile decreases by 97.2% in non-liquefiable condition and 82.7% in liquefiable condition when the axial load reduces from 1327 to 0 kN. So, the designer should be considered both extreme scenarios for safe and economical design. Also, it is noticed that the buckling capacity of pile is improved significantly by using larger diameter pile and the bending capacity is increased by selecting higher grade of concrete. It is concluded that the bending and buckling failure mode may be avoided by selecting a suitable combination of material strength and pile geometry.

Dynamic Response of a Four-Pile Group Foundation in Liquefiable Soil Considering Nonlinear Soil-Pile Interaction

Piles, which are always exposed to dynamic loads, are widely used in offshore structures. The dynamic response of the pile-soil-superstructure system in liquefiable soils is complicated, and the interaction between the pile and soil and the pile volume effect are the key influencing factors. In this study, a water-soil fully coupled dynamic finite element-finite difference (FE-FD) method was used to numerically simulate the centrifuge shaking table (CST) test of a four-pile group in saturated sand soil. An interface contact model was proposed to simulate the pile-soil interaction, and a solid element was used to consider the volume effect of the pile. The acceleration responses of the soil and pile, settlement deformation, excess pore water pressure, and bending moment were examined. The results show that the bending moment response of the two piles parallel to the shaking direction show minor differences, while the two piles perpendicular to the shaking direction show almost the same distribution. The values of excess pore water pressure at the same depth but different azimuth angles around the pile are also different. The numerical simulation can accurately reproduce soil deformation and pile internal force during and after dynamic loading.