Final Deflection Research Articles

Elastoplastic plate shakes down under repeated impulsive loadings

When subjected to repeated dynamic impacts at identical load level, a metallic monolithic beam/plate may reach a stable state wherein measurable deformation ceases (i.e., shakedown in elastic state) after undergoing a sequence of elastoplastic deformations, which has been termed as “pseudo-shakedown” (P-S) (Jones, 1973, Shen and Jones, 1992). While the response of a single beam/plate under repeated low-velocity impacts has been thoroughly studied, its dynamic behavior under high-velocity impacts, such as explosive or alternating impulsive loads, is difficult to measure experimentally, due mainly to high costs and setup challenges. In the current study, the method of metallic foam projectile impact was employed to produce repeated impulsive loadings on a fully-clamped elastoplastic monolithic plate made of L907A (a Chinese standard shipbuilding steel). Its dynamic responses, including mid-point deflection versus time histories, final deflections, and deformation modes after each impact, were systematically measured. The phenomenon of dynamic shakedown was observed. To further explore this phenomenon, the method of finite elements (FE) was employed to simulate the repeated impulsive impact test, and its prediction accuracy was validated against experimental results. Unlike an elastoplastic (e.g., steel) monolithic plate subjected to repeated low-velocity impacts, which exhibits zero plastic energy dissipation in the P-S (pseudo-shakedown) state, the same plate under repeated high-velocity impacts shows a small level of plastic energy dissipation in the P-S state, mainly due to more extreme loading conditions. The initial impact momentum, yield strength, and tangent modulus of the material the plate is made of significantly affect both the stable deflection in the P-S state and the number of impacts needed to reach it, while the elastic modulus has limited influence. A modified dimensionless impulse loading number, accounting for the strain-hardening effect, is proposed. An approximately linear relationship between stable deflection in the P-S state and impulsive loading is found in dimensionless form.

Performance analysis and design method of strengthening beam-column welded connections against progressive collapse

To address the insufficient collapse resistance of the beam-column welded connection (BWC), this study proposes a strengthening beam-column welded connection with truss elements (BWCTE). A static test on a BWCTE specimen with a composite slab was conducted to investigate its failure pattern, final deflection, and the evolution of axial force, bending moment, and collapse resistance. The results indicate that the addition of truss elements increases the peak load and corresponding deformation of BWCTE by 108.6 % and 27.3 %, respectively, compared to BWC. Moreover, the axial force in the composite beam of the BWCTE specimen achieved the yield axial force, facilitating the complete development of catenary action and optimizing beam performance. Subsequently, primary parameters of the truss element were analyzed using refined numerical models. It is recommended that the projected length of the inside leaning limb is within 0.5 to 0.7 times the height of the steel beam, and the thickness of each limb is within 0.6 to 1.2 times the thickness of the beam flange. Then, the working mechanism of BWCTE was explored through theoretical analysis. The resistance process of BWCTE can be divided into elastic, elastic-plastic, plastic, transition, and catenary stages. The loading and deformation synergies between truss elements and composite beams enable the formation of double plastic zones and double strengthening zones at the beam root, effectively delaying the rupture of the stretched beam flange. Finally, a design method for BWCTE is proposed according to theoretical and numerical analysis.

Experimental and numerical study on damage behavior of air-backed steel-concrete-steel composite panels subjected to underwater contact explosion

The damage behavior and explosion resistance of air-backed steel-concrete-steel (SCS) composite panels subjected to underwater contact explosions were investigated experimentally and numerically. Firstly, the underwater explosion experiments of the SCS panels were conducted using the novel test setup, and the final damage morphology and residual deflection of these panels were obtained. Secondly, the corresponding finite element model was established in LS-DYNA and validated against the test results, based on the refined numerical modelling, the damage process of the SCS composite panel under 200 g underwater contact explosion was reproduced. After that, the damage mechanism of the SCS panels was revealed through the analysis of internal energy absorption and stress wave propagation inside the SCS panels. Subsequently, the damage behavior of the SCS panels when subjected to underwater and air contact explosions was compared. Finally, a series of parametric analysis were performed to explore the effects of the material strength and structural form on the explosion resistance of SCS panels. Both the experimental and numerical results indicate that the SCS panels suffered global damage. The core concrete absorbed more than 80 % of the explosion energy and the restraint of the steel plates effectively reduced the spalling damage of the core concrete. The SCS composite panel makes full use of the advantages of concrete and steel panels, resulting in superior underwater explosion resistance.

Direction-dependent bending resistance of 3D printed bio-inspired composites with asymmetric 3D articulated tiles

Inspired by the protective armors in nature, composites with asymmetric 3D articulated tiles attached to a soft layer are designed and fabricated via a multi-material 3D printer. The bending resistance of the new designs are characterized via three-point bending experiments. Bending rigidity, strength, and final deflection of the designs are quantified and compared when loaded in two different in-plane and two different out-of-plane directions. It is found that in general, the designs with articulated tiles show direction-dependent bending behaviors with significantly increased bending rigidity, strength, and deflection to final failure in certain loading directions, as is attributed to the asymmetric tile articulation (asymmetric about the mid-plane of tiles) and an interesting sliding-induced auxetic effect. Analytical, numerical, and experimental analyses are conducted to unveil the underlying mechanisms.

Predicting the dynamic response of elastic-plastic beams by dimensional analysis

Elastic-plastic beams subjected to dynamic loading are widely found in engineering. However, due to the complex coupling of geometric and material nonlinearity, there is no complete analytical solution available. In this paper, based on energy conservation and dimensional analysis, a dominant dimensionless number, the loading intensity ξ, is proposed. Including both the effects of geometry, material and load, ξ could be used to predict the significant responses of an elastic-plastic beam under uniformly pressure loading, such as energy ratio, deflection ratio and deformation mechanism. With combination of loading intensity ξ and dimensionless stiffness β, the dimensionless maximum and final deflections of elastic-plastic beams under pressure loading can be predicted directly. Dimensionless numbers of beams with different cross-sections, or under different loading forms are also analyzed and confirmed.Then, elastic effect over dynamic response of elastic-plastic beams is analyzed. For final deflection, it is found ξ>5 is the applicability of theoretical solution based on rigid, perfectly plastic (R-PP) material simplification. However, R-PP results can't be used in initial plastic hinge location and subsequent plastic zone evolution, even for very large ξ.Using these dimensionless numbers, experimental or simulation data could be expressed in a normalized and comparable form, and the physical mechanisms will be more intuitive and clearer, which is valuable for scaled dynamic tests.

The dynamic response of composite auxetic re-entrant honeycomb structure subjected to underwater impulsive loading

The researches on dynamic responses of underwater impulsive loading have been conducted. However, the previous study mainly concentrated on metal sandwich structure and fixed supported boundary. The relative research on composite auxetic re-entrant honeycomb structure and simply supported boundary are rarely. In this paper, the effect of the gradient form and relative density on impact resistance performance of composite auxetic re-entrant honeycomb structure was experimentally and numerically investigated. The one-stage light gas gun was applied to provide initial kinetic energy of the fly plate, and the diffuser-type shock tube was utilized to generate and propagate exponential decaying shock wave. The pressure–time curve was respectively amplified and recorded by the charge amplifier and oscilloscope. The response speed, final deflection of rear panel and failure mode of cores and panels were used to evaluate impact resistance of composite auxetic re-entrant honeycomb structures. Moreover, acoustic-structure interaction algorithm was applied to simulate impact course of specimens in Abaqus/Explicit. The results between experiment and numerical simulation exhibited good consistency. The results indicated that the positive gradient form could excessively slow down response speed of rear panel by dissipating energy of shock wave, and the average gradient demonstrated smaller final displacement of rear panel and less failure compared with graded structures.

SHEAR BEHAVIOUR OF REINFORCED-CONCRETE BEAMS INCORPORATING IRON FILINGS AS SAND REPLACEMENT

This study examined the influence of partial sand replacement with iron filings on the mechanical and physical characteristics of concrete, as well as conducted experimental tests of the shear behaviour of reinforced-concrete beams. Four replacement rates were used in this study, i.e., 5 %, 10 %, 20 %, and 30 % with a reference mixture containing no iron filings. At ages 7, 14, and 28 days, mechanical property tests (slump, density, ultrasonic pulse velocity, compressive strength, and splitting strength tests) were conducted. In addition, the shear behaviour of five reinforced-concrete beams with the same replacement rates (0 %, 5 %, 10 %, 20 %, and 30 %) were experimentally tested. Tests were conducted to determine the ultimate load failure, final deflection, energy absorption, stiffness, ductility index, compressive stress, and crack formations. According to the results, the correlation between the slump test and iron filings is positive; however, that for absorption is negative. With a higher percentage of iron-filing replacement, the density and ultrasonic pulse velocity increased. For specimens with 30,00 % iron filings, the densities, pulse velocities, and slumps were raised by 6,27 %, 2,44 %, and 58,33 %, respectively, compared to the reference specimens, whereas the absorption rate decreased by 20,00 %. Having 20,00 % iron filings produced the maximum compressive and splitting strengths of 28,00 %, which was 4,60 % higher than the reference mixture, whereas 30,00 % iron filings produced the highest flexural strength, which was 9,50 % higher than the reference mix. The findings of beam testing revealed that increasing the iron-filing content in concrete beams increased the final failure load, final deflection, ductility index, and energy absorption by 6,70 %, 10,29 %, 11,30 %, and 35,00 %, respectively. The initial and secant stiffnesses decreased at rates of 12,60 % and 3,10 %, respectively.

Elastic effect on the final deflection of rigid-plastic square plates under pulse loading

Rigid-perfectly plastic (R-PP) models are widely employed in the study of structural impact dynamics. However, due to the complexity of dynamic elastic-plastic behavior and the limitations of numerical simulation, it is of great significance to evaluate the elastic effect on the structural response to pulse loading. This paper examines the validity of the R-PP theoretical solutions on large deflection of pulse-loaded square plates. First, by exploring the characteristic of “plastic membrane” and considering the effect of membrane forces and bending moments on energy dissipation, an energy ratio R and a characteristic time ratio are precisely defined. Then based on the R-PP complete solutions recently developed for square plates under rectangular pressure pulse, the discrepancies in final deflection and in saturated impulse between the R-PP theoretical predictions and the elastic-perfectly plastic (E-PP) simulation results are evaluated and elaborated. It is revealed that the discrepancy in final deflection is dependent on the dimensionless stiffness ζplate and the dimensionless pulse magnitude λ. Moreover, the discrepancies in final deflection are compared between square plates and beams via a thorough analysis of key parameters, indicating that most characteristics of the elastic effect are similar for both cases, i.e., the R-PP solutions for both square plates and beams can reliably provide theoretical predictions for engineering applications if energy ratios R>5, with no limitation on the pulse duration. With the same geometric and material parameters, however, the energy ratio R of square plates is about twice that of beams, the discrepancy in final deflection of plates is larger than that of beams, but the absolute value of the discrepancy in final deflection for the clamped square plates remains in the order of 1/(1.5R) and can be bounded by 1/[4λ(λ-1)].

A state-of-the-art review on reinforced concrete slabs strengthened by frp sheets under monotonic, impact and repeated loading

Composites made of fiber-reinforced polymer (FRP) have gained popularity as new high-performance material for concrete buildings in now days. The advantages of FRP composites include high strength, lightweight, and corrosion resistance. This paper’s primary objective is to assess the affect of FRP strips on the strengthening and repair of plain and reinforced concrete slabs. under the monotonic, impact, and repeated loading. According to studies’ observations, applying FRP strips to RC slabs significantly affects the final load and deflection. The number and positioning of FRP sheets improve the performance of slabs. The failure load magnitude of strengthened slabs would increase as slab thickness, concrete compressive strength, and sheet thickness increase. The ultimate load capacity was increased by (27-52%), depending on the FRP strengthening strategy used. GFRP sheets could be employed for improving or enhancing the impact strength of concrete structures. Externally attached GFRP sheets gave good resistance for reinforced concrete slabs against typical explosive blast.

PH-Sensitive Hydrogel Bilayers: Investigation on Transient Swelling-Induced Bending through Analytical and FEM Approaches.

pH-responsive hydrogels are recognized as versatile sensors and actuators due to their unique time-dependent properties. Specifically, pH-sensitive hydrogel-based bilayers exhibit remarkable bending capabilities when exposed to pH-triggered swelling. This study introduces a semi-analytical technique that combines non-linear solid mechanics with ionic species transport to investigate the bending behavior of such bilayers. The technique is validated through numerical simulations, exploring the influence of kinetic and geometric properties on bilayer behavior. The results highlight the significance of the interfacial region, particularly in configurations with lower hydrogel geometric ratios, which are susceptible to rupture. The study also uncovers the benefits of a lower hydrogel layer ratio in improving the swelling rate and final deflection, with a stronger effect observed in the presence of a buffer solution. Additionally, the compressibility of the elastomer contributes to the durability of the final bent shape. These findings enhance our understanding of pH-sensitive hydrogel-based bilayers and offer valuable insights for their design and optimization in diverse applications.

Behaviour of steel open web joist under geometric nonlinearity

This work focuses on a parametric study using theoretical and analytical investigations to determine the geometric nonlinearity response of an open web steel joist under non-uniform bending. To achieve this, a preparatory analysis of three steel design standards used in the creation of various combinations utilizing slenderness ratios was conducted. A total of 40 finite element models were produced using the ABAQUS software, each of which was distinguished based on the slenderness ratio and was modelled using typical linear material characteristics. The open web steel joist's maximum deflection within the elastic limit was evaluated theoretically and compared analytically. The comparison between the load and the final deflection behaviour, which was determined theoretically and analytically, shows excellent collaboration and validates the analytical modelling. The results show that, despite the material's linearity being preserved, load vs. deflection graphs is becoming nonlinear. This demonstrates that geometric nonlinearity significantly affects the final capacity and deflection of open web steel joists. Also, with more sectional depth, geometric nonlinearity has a greater effect. Therefore, this work reveals that while analysing the behaviour of open web steel joists, the effects of geometric nonlinearity must be taken into account.

RESEARCH OF THE STRENGTH AND DEFORMABILITY OF ROAD SLABS REINFORCED WITH SMALL DIAMETER COMPOSITE REINFORCEMENT

Scientific work is devoted to research of stress-strain state of PD2-9,5 road slabs, reinforced with identical frames made of fiberglass reinforcement and metal reinforcement A500C of the 10th diameter. In order to verify the hypothesis regarding the possibility of equal-strength replacement of metal reinforcement with composite reinforcement of a smaller diameter, glass composite reinforcement of the 7th diameter was used to reinforce the slab. To determine the actual bearing capacity, due to the application of a uniformly distributed load, a calculation scheme with a "beam" slab, i.e., resting on two supports, was applied. During the experiment, it was determined that the appearance, formation, and opening of normal cracks in both tested slabs corresponds to the "classic" nature of crack formation in reinforced concrete elements operating in bending. After the destruction of the slab reinforced with fiberglass composite reinforcement, numerous structural cracks of a mesh nature were recorded, with different degrees of branching, mainly in the lateral central part and in the lower (stretched) zone. The total final deflection in the center of the slab reinforced with fiberglass composite reinforcement at the time of failure was 3,41 cm, which significantly exceeds the permissible value for the span length L < 3 m. At the same time, the total deflection in the center of the slab reinforced with metal reinforcement at the current maximum uniformly distributed load ( without complete destruction of the slab) is 1,06 cm, which meets the generally accepted construction requirements. It was established that the actual bearing capacity of the road slab reinforced with A500C metal reinforcement is higher by 2,3 times than the bearing capacity of a slab with similar fiberglass composite reinforcement. This fact does not give grounds for asserting the effective use of Ø7 mm fiberglass composite reinforcement as a conditionally “equal-strength” replacement of Ø10 mm class A500C metal reinforcement when reinforcing elements of a similar type. To ensure structural requirements, it is necessary to significantly increase the diameter of the applied composite reinforcement, or, as an option, use combined reinforcement with a simultaneous combination of metal and composite reinforcement. Keywords: strength, composite reinforcement, stress-strain state, road slab.

Effect of Fire on Reinforced Concrete Beams with FRP and Conventional Steel at Limited Time of Fire

Abstract The aim of this study is to investigate the behavior of RC concrete beams reinforced with basalt, carbon, glass fiber reinforced polymer bars and conventional steel. A comparison between the results has been performed to investigate and study the effect of fire on reinforced concrete beams considering the following items: (flexural capacity, deflection behavior and crack pattern). It is noticeable that the use of FRP bars significantly increased the ultimate load of the specimens, where the percentage of increase ranged between 34 - 73 % of the ultimate load of the specimen C-S under static load. The greatest ultimate load was reached the beam that was reinforced with carbon bars (CFRP). It was also noticed able that the use of FRP rods significantly increases the deflection of the beams. The percentage of increase was between 45 - 170 % of the final deflection of the C-S specimen under static load. It was noted that the effect of the fire on the beams reinforced with fiber bars (FRP), where the efficiency of bearing capacity of beams after fire decreases by 11 to 18 % of the actual efficiency of bearing capacity of beams control. As for the beam reinforced with conventional steel bars, its efficiency was reduced by 15 % from the actual capacity.

Distributed fibre optic inclinometer with cloud-based monitoring system

Geotechnical instrumentation and monitoring are important aspect of controlling subsurface ground movement, particularly in deep excavations and forewarning of geological disasters such as landslides, land subsidence, ground fissure, and surface collapse. A borehole inclinometer is an example of the established method to monitor such ground movements. For real-time data, a series of in-placed inclinometer probes are installed inside the borehole casing to provide the lateral displacement response over time. The limitation of the conventional system is the high cost and the practicality of inserting a high number of sensing probes into the casing for better measurement accuracy. Recent advancement in Distributed Optical Fibre Strain Sensing (DOFS) enables the incorporation of DOFS as a fibre optic (FO) inclinometer with lateral displacements to be plotted at centimetres spacing and is unaffected by the gauge lengths between the probes. This study enhances the FO inclinometer by developing a web-based application (SmartGeopipe©) to automate data acquisition which also includes complex data processing for the final pipe deflection profile visualisation. The FO inclinometer comprised of optical cables attached externally onto a remodified inclinometer casing and connected to a Brillouin Optical Time Domain Analysis (BOTDA) strain analyser. A standard installation procedure was established to safely secure the sensors during the casing installation process inside the borehole. SmartGeopipe© software is written using a predominantly monolithic Python / Cython backend and a multi-page frontend built with HTML, CSS, and JavaScript ES5 languages. All the computation work and data storing are done in a cloud server and SQL database, respectively. A case study of a station box excavation as part of the Mass Rapid Transit (MRT) tunnelling project was chosen to validate the performance of the FO inclinometer and the web application. Data from the FO inclinometer corroborated well with the manual measurements of the inclinometer probe. This ability supports the realization of an early warning system as an engineering control for hazard management in civil engineering infrastructure projects.

Elastic effects on the dynamic plastic deflection of pulse-loaded beams

Beams under intense dynamic pulse loading may experience large elastic-plastic deformation. Despite numerous studies have been conducted based on the rigid-perfectly plastic idealization of material, it is of great interest in both theoretical modeling and practical application to characterize and evaluate the effect of elastic deformation on the dynamic behavior of structures. This paper is aimed to examine the range of applicability of rigid-plastic theoretical solutions on large deflection of beams in response to dynamic pulse loading. The energy ratio R and the characteristic time ratio are first precisely defined by referring to the characteristics of a “plastic string”, which represents the ultimate status of beams under very large deformation. Based on the recently published complete solutions on the dynamic response of fully-clamped and simply-supported rigid-plastic beams subjected to uniformly distributed rectangular pressure pulse, the discrepancies in final deflection and in saturated impulse of the rigid-plastic theoretical predictions from the elastic-plastic simulation results are evaluated and analyzed. It is revealed that if the energy ratio R>5 (with no limitation to the pulse duration), the rigid-plastic solutions can provide reliable predictions on final deflection and saturated impulse for the usage in engineering design. Then, the effects of the key dimensionless parameters related to the energy ratio R (e.g., the structural and material parameters as well as the loading one) on the discrepancies in final deflection and in saturated impulse are thoroughly examined. Finally, a unified dimensionless stiffness is identified to characterize the combined effect of structural and material parameters. For the cases of ζ≤1.581, which represent most of the practically used beams, 1/(2R) and 1/(3R) could provide upper bounds to the absolute value of the discrepancy in final deflection for fully-clamped and simply-supported beams, respectively.

Effect of Screw Head- and Hook-on Bond Behavior of Flamingo Shear Reinforcing Technique in Concrete

An alternative reinforcing shear technique was proposed during this work in place of the traditional vertical stirrups. Three reinforced concrete beams with dimensions of (200 * 300) mm and a length of 1800 mm were used. A reference control beam with traditional vertical stirrups (RCWS) and two beams reinforced with flamingo with a fixed angle of 45° and free ends (50% and 50%) from effective depth were used, while the main variable was the bonding process with concrete using a screw head (FWS) and hook (FWH). In the flamingo technique, the hook was used and the screw head was used at an equal angle of 130 degrees. A significant improvement was found in the shear capacity of the beam compared to the reference sample. Also, using a screw head made the shear capacity 13.22% higher than using a hook and improved the shear ductility, final deflection, and crushing behavior of beams made with the flamingo technique.

PUFJ (PolyUrethane Flexible Joints) as an innovative polyurethane system for structural and non-structural bonding of timber elements

PolyUrethane Flexible Joints (PUFJ) as an innovative adhesive system has been developed by a team of researchers from the Cracow University of Technology (CUT) for several years. Initially, the research focused mainly on joining masonry and reinforced concrete elements. Due to environmental concerns and climate changes, further advancement of the PUFJ system was focused on the technology development based on connecting natural materials such as wood and wood-based materials. In 2019, the cooperation of the CUT with a private company resulted in the implementation of the PUFJ system for the construction of innovative connections in a prefabricated timber frame construction of a family house near Cracow. Currently, further research are carried out focused on the complex understanding of behaviour of adhesive bond used in structural and non-structural timber bonding, taking into account different species of wood (pine, spruce, beech, douglas fir) and a different thickness of the flexible adhesive layer (from 1 mm to 30 mm). The article contains the properties of the PUFJ system, describes variants of the available applications (wet application in form of liquid substance curing in time or dry application as a prefabricated bonding layers glued to the elements with a thin adhesive layer). Examples of double-lap shear connections and laminated beams made of douglas fir wood of C24 class and Sika®PS polyurethane flexible layer are presented. All specimens were constructed with three various flexible adhesive thicknesses of 1, 2 and 4 mm. The influence of elevated temperature on the load capacity of the connection and on the final deflection was tested. The tests were conducted at four temperature levels (20, 40, 60 and 80°C).

Flexural Performance of Sustainable Fly Ash Based Concrete Beams

The demand for concrete is high due to its solid strength and flexibility. To produce more concrete requirement of cement is very large. The production of concrete releases CO2 into the atmosphere. This can lead to global warming. By including other substances that have a cementations tendency, cement consumption can be decreased. To lower the cement consumption in concrete, a variety of pozzolanic ingredients are being used. It is being investigated whether fly ash can replace cement. Flexural tests were performed on reinforced concrete beams with fly ash contents ranging from 0% to 60% and binder contents of 400 and 450 kg/m3 with a water binder ratio of 0.4. The beam size is 100X200mm with a length of 1.2 m. It was observed that all the beams failed under compression in both mixes. In both, the mixer’s depth of crack is reduced when compared with the fly ash incorporated beams with no-fly ash concrete beams. The quick spread of the fracture is slowed down by the addition of fly ash to concrete. The filler effect, which aids in pore refinement and prevents the creation of cracks as well as the enlargement of propagated cracks, is initiated in the concrete as the fly ash content rises. According to the experimental findings, the load capacity of RC beams containing 30% fly ash is the greatest of all the beams. The outcomes for exhibit the same behaviour. Compression resistance. Finally, it was shown that, versus ordinary concrete RC beams, the inclusion of fly ash boosted the beam’s capacity to carry loads by up to 40% fly ash replacement. Whenever the fly ash content is increased by up to 40% replacement, the RC beam’s final deflection increases.

Influence of slab deflection on the out-of-plane capacity of unreinforced masonry partition walls

Severe damage of non-structural elements is noticed in previous earthquakes, causing high economic losses and posing a life threat for the people. Masonry partition walls are one of the most commonly used non-structural elements. Therefore, their behaviour under earthquake loading in out-of-plane (OOP) direction is investigated by several researches in the past years. However, none of the existing experimental campaigns or analytical approaches consider the influence of prior slab deflection on OOP response of partition walls. Moreover, none of the existing construction techniques for the connection of partition walls with surrounding reinforced concrete (RC) is investigated for the combined slab deflection and OOP loading. However, the inevitable time-dependent behaviour of RC slabs leads to high values of final slab deflections which can further influence boundary conditions of partition walls. Therefore, a comprehensive study on the influence of slab deflection on the OOP capacity of masonry partitions is conducted. In the first step, experimental tests are carried out. Results of experimental tests are further used for the calibration of the numerical model employed for a parametric study. Based on the results, behaviour under combined loading for different construction techniques is explained. The results show that slab deflection leads either to severe damage or to a high reduction of OOP capacity. Existing practical solutions do not account for these effects. In this contribution, recommendations to overcome the problems of combined slab deflection and OOP loading on masonry partition walls are given. Possible interaction of in-plane (IP) loading, with the combined slab deflection and OOP loading on partition walls, is not investigated in this study.

Numerical simulations of the sliding impact between an ice floe and a ship hull structure in ABAQUS

This paper studies the hull structural responses of a steel grillage subjected to sliding ice loads, which have been rarely investigated in the literature. Sliding ice loads are modelled using nonlinear finite element analysis (NLFEA) method; and Abaqus Explicit is adopted as the numerical solver. Deformations and damages of ice and steel are both considered. A rigid ice model is also simulated for comparison purposes. The hull’s local structural responses under different load cases, including deformation, contact forces, and energy distribution, have been analysed. The effects of static structure-to-structure friction coefficient and the relative stiffness between ice and structure are studied. It is found that the deformation of structures will increase the total friction coefficient, which is defined as the ratio of the friction force (the tangential contact force) to the normal contact force. When the ice floe is considered rigid, the static friction coefficient has little effect on the local structural responses of the hull. If using a higher-strength steel material for hull structures in the ice-classed ship design, the hull’s deflection and total friction decrease, and the hull dissipates less energy as expected. Moreover, stationary load cases with the same loading condition in the normal direction as sliding load cases are also simulated. When using the deformable ice material model, the simulation results show that the hull’s final contact forces and deflection in stationary load cases are larger than those in sliding load cases. Besides, the effect of steel material is more significant in stationary load cases than in sliding load cases.