Thin Steel Plate Research Articles

Study on stability improvement by applying electromagnetic force to edge of non-contact-gripped thin steel plate

Study on stability improvement by applying electromagnetic force to edge of non-contact-gripped thin steel plate

Research on Failure Modes and Key Parameters of Corrugated Steel Shear Walls

The corrugated steel plate shear wall is an effective and economical lateral load resisting system. And the thin steel plate is easy to buckle. And it is necessary to use much more thickness or ribs to prevent the buckle at out of plane direction, which is not economical or complicated to construct. A number of corrugated shear walls are analyzed by nonlinear static pushover analysis method. And failure modes, buckling, the ultimate capacity, and shear force-drift curves are studied. The results showed that the corrugated steel plate can be designed according to the failure modes, in order to have a desirable failure mode that the corrugated steel plate yield before buckling.

Simulation on microscopic deformation behavior of engine gasket

Engine gasket is the thin steel plate with coatings. Its compressive deformation affects the height of engine assembly, which changes combustion chamber’s volume and then influences engine performance. In this paper, the assembly simulation of head, block and gasket was studied. Then a further simulation takes the thin coatings on steel sheet into consideration. In the second simulation, gasket’s partial micro-model in micron-scale meshes was established and deformation of coatings was analysed. The combination of deformations explores the cause of fluctuations of gasket’s tightened thickness and obtains more precise numerical results of tightened thickness at different positions. Moreover, a lead pellet test was carried out to verify the results of tightened thickness calculation.

水平方向位置決め制御を用いた磁気浮上搬送極薄鋼板

Thin steel plates are widely used in various industrial products. However, there are problems where deterioration of surface quality and metal plating occurred by transporting. As a solution to these problems, a noncontact transport of steel plate using electromagnetic force has been proposed. However, there is a risk that side slipping or the dropping of the plate may occur. Therefore we have proposed the addition of electromagnetic actuators to control the horizontal motion of levitated steel plate. In this study, we examined the change in the levitation stability during non-contact transport with the addition of positioning control in its horizontal direction in the case of changed transport coditions. As a result, it is confirmed that the application of a magnetic field in the horizontal direction improves the levitation stability of transported thin steel plate in different transport conditions.

Moment-curvature Model for Steel Plate-concrete Composite Beams

The rapid development of composite structures has led to a new design concept of the steel plate-concrete composite beam in which a thin steel plate is attached to the reinforced concrete beam. The shear connection is established by the use of headed studs and the joined parts can act as a unit due to the adequate bond between the steel and concrete. The behavior of this type of structures can be classified as intermediate between composite and reinforced concrete structures.The experimental studies have shown that the methods described in standard codes allow to determine the ultimate load of the structure, while the structure's deflection is underdetermined. More sophisticated analyses of beams are more accurate but they are used in practical design rather reluctantly. The purpose of this paper is to present a moment-curvature model which can be used in simplified calculation of deflection of steel plate-concrete composite beams. Instead of adopting the complex theoretical analysis, a trilinear model is represented by pre-cracking, post-crack and post-yielding stages. The additional deflection due to shear slip at the interface plane is taken into account. The slip effect always exists both in fully and partially composite beams and experimental studies have shown that it has a significant impact on the response of the structure. Tension stiffening effects are also considered since beam rigidity is reduced when cracking is developing due to an increase of the applied load. For validation purposes a theoretical analysis based on the presented model was performed and compared with the experimental results. The predicted results of the analytical studies were compared with the measurements of the tested beam to confirm the validity of the proposed method. It was confirmed that including the shear slip effect has significantly improved the accuracy of prediction.

Design and validation of polarity-changeable magnetizer for encoding patterns on ring-like rotary encoders

Through numerical simulations and calibrated experiments, the aim of the work presented in this paper is placed on the development of a polarity changeable magnetizing platform for a rotary magnetic encoder using a permanent magnet and thin silicon steel plate. Parameter studies are conducted via finite-element analyses to obtain optimized geometric design parameters for the magnetizer, leading to desirable magnetic flux density and effective magnetized patterns on the magnetic media.

Finite Element Analysis of Self-centering Moment Resistant Frames with and without Steel Plate Shear Wall

The Northridge earthquake on January 1994 damaged a large number of buildings all through Los Angeles. The most recurrent pattern of structural damage was the brittle failures at beam column junction in steel moment-resisting frames (MRF's)[6] This event brought out the need for further improving the Moment Resistant Frames and its connections. A new system of Moment Resisting Frames (MRF) commonly known as Self-Centering Moment Resisting Frames (SC-MRF) was developed. These designs are capable of resisting the seismic loads without sustaining much damage. The paper studies the behaviour of Self-Centering Moment Resisting Frames (SC-MRF) with and without steel plate shear walls subjected to cyclic loading. A detailed three dimensional finite element modeling using plate elements available in ANSYS FEA code is done. Geometric and material nonlinear stress analysis of the frame and a detailed comparison of the frame with and without steel plate shear walls is done. It can be observed that the sway of the SC-MRF frame is much higher than that of a conventional frame, but by introducing a thin steel plate shear wall this deformation can be brought down to a much lower value.

機械スイッチ式非線形回路を用いた振動発電素子の高出力化

A miniature piezoelectric vibration energy harvester represents one promising power source for IoT (Internet of things) device. Recently, a SSHI (Synchronized Switch Harvesting on Inductor) interface was developed to enhance its output power. However, use of external power source or of complicated circuits for switching On/Off poses a practical problem. To address these issues, we propose a mechanical switch for SSHI interface. We employed ball spring plunger and stainless steel thin plate for the mechanical switch. We demonstrated that the mechanical switch properly works as a SSHI interface. The miniature prototype harvester achieved 1.2 mW at the frequency of 35.6 Hz under the acceleration of 0.55 G, a 1.7-fold increase over the standard circuit.

Experimental study on the response of thin aluminium and steel plates subjected to airblast loading

This work presents results from an experimental investigation on the influence of stand-off distance on the dynamic response of thin ductile plates subjected to airblast loading. The square plates had an exposed area of 0.3×0.3 m2 and were manufactured from two different materials, i.e., medium-strength steel and low-strength aluminium. The airblast loading was generated by detonating spherical charges of plastic explosive at various stand-off distances relative to the centre of the plates. Piezoelectric pressure sensors were used for pressure recordings, and synchronized with two high-speed cameras in a stereoscopic setup to capture the response of the targets. The 0.8 mm thick plates were painted with a speckle pattern to measure the transient deformation fields using a three-dimensional digital image correlation (3D-DIC) technique. The tests covered the entire range of structural response from complete failure at the support to a more counter-intuitive behaviour where the permanent mid-point deflection was in the opposite direction to the incident blast wave due to reversed snap buckling. The synchronization of the pressure and displacement measurements enabled a thorough examination of the entire experiment. The trend in all tests was that the maximum response is driven by the positive impulse from the airblast, as it occurred after the positive duration of the pressure pulse. However, depending on the intensity of the blast load and the structural characteristics, elastic effects and the negative phase could play an important role in the final configuration of the plate. Comparison of the permanent deflection and the measurements from digital image correlation confirmed that this technique is capable of accurately measuring the structural response at high loading rates.

Experimental strength assessment of thin steel plates with a central elongated circular opening

This work assesses the ultimate strength of experimentally tested steel plates with a large central elongated circular opening, subjected to uni-axial compressive load. A series of experimental tests have been carried out on plates that were part of a real structure, which represents a scaled midship section of single hull tanker ship, tested in a corrosive environment in direct contact with seawater. One elongated circular opening shape with different sizes is analyzed and the effect of the opening size on the ultimate strength is investigated. The force–displacements relationships are presented and the dissipated energy is analyzed. Stress–strain relationships, resilience and toughness have been evaluated. The collapse modes are discussed and the ultimate strength has been compared with recently published studies showing a good agreement in the trend.

On the dynamic plastic response of steel membranes subjected to localised blast loading

Permanent plastic deformation is expected when close-in blasts due to e.g. detonation of Improvised Explosive Devices (IED's) hit thin metallic targets. A circular thin steel plate i.e. a membrane is studied in the present work subject to a general form of a localised blast loading. The spatial shape of the pulse is fixed and different temporal shapes are investigated. Dynamic analyses are conducted and the permanent transverse displacements are found for each case.For high amplitude pulse loads of short duration, it was found that the permanent transverse displacement can be found by replacing the load by an impulse without the loss of accuracy. Excellent correlation with numerical simulations obtained from ABAQUS/Explicit is achieved. The predicted final displacements for different pulse shapes are also found to be similar, thus where membrane action is dominant, the response is insensitive to pulse shape.

Calibration and data quality systems of the ATLAS Tile Calorimeter during the LHC Run-I operations

The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It consists of thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. The calibration scheme of the Tile Calorimeter comprises Cs radioactive source, laser and charge injection systems. Each stage of the signal production of the calorimeter from scintillation light to digitization is monitored and equalized. Description of the different TileCal calibration systems as well as the results on their performance in terms of calibration factors, linearity and stability is given. The data quality procedures and efficiency of the Tile Calorimeter during the LHC Run-1 data-taking period are presented as well.

Effect of gas detonation on response of circular plate-experimental and theoretical

A series of experimental results on thin mild steel plates clamped at the boundary subjected to gas detonation shock loading are presented. Detonation occurred by mixing Acetylene (C2H2)-Oxygen (O2) in various volume ratio and different initial pressure. The applied impulse is varied to give deformation in the range from 6 mm to 35 mm. Analytical modeling using energy method was also performed. Dependent material properties, as well as strain rate sensitivity, are included in the theoretical modeling. Prediction values for midpoint deflections are compared with experimental data. The analytical predictions have good agreement with experimental values. Moreover, it has been shown that the obtained model has much less error compared with those previously proposed in the literature.

Analytical investigation of thin steel plate shear walls with screwed infill plate

A behavior model for screw connections is developed to provide a better representation of the nonlinear response of thin steel plate shear walls (TSPSWs) with infill plates attached to the boundary frame members via self-drilling screws. This analytical representation is based on the load-bearing deformation relationship between the infill plate and the screw threads. The model can be easily implemented in strip models of TSPSWs where the tension field action of the infill plates is represented by a series of parallel discrete tension-only strips. Previously reported experimental results from tests of two different TSPSWs are used to provide experimental validation of the modeling approach. The beam-to-column connection behavior was also included in the analyses using a four parameter rotational spring model that was calibrated to a test of an identical frame as used for the TSPSW specimens but without the infill plates. The complete TSPSW models consisting of strips representing the infill plates, zero length elements representing the load-bearing deformation response of the screw connection at each end of the strips and the four parameter spring model at each beam-to-column connection are shown to have good agreement with the experimental results. The resulting models should enable design and analysis of TSPSWs for both new construction and retrofit of existing buildings.

Magnetic Levitation Control by Considering the Twisting Mode of a 0.18 mm Thick Steel Plate

Although adopting magnetic levitation techniques in a process line for very thin steel plates is expected to maintain the high quality of the plate surfaces, the control for levitation and guidance is very difficult. However, we have already established the stable magnetic levitation and guidance control for 1.6 mm thick steel plates. In this paper, magnetic levitation for a thinner steel plate (0.18 mm thickness) is our study target, because stable levitation of thinner steel plates will lead to stable levitation of large steel plates, similarly. In order to realize such a non-contact system, we have to take account of the vibration of the plate. This paper will realize the stable magnetic levitation of a 0.18 mm thick steel plate by adopting the twisting-mode control.

Measurement of circumferential Lamb waves using a line-focus poly(vinylidene fluoride) transducer and cross correlation waveform analysis

This paper presents a method for measuring circumferential Lamb waves propagating on a cylindrically curved thin plate. The measurement is carried out using a wideband and line-focused poly(vinylidene fluoride) transducer along with a defocusing waveform measurement method. After synthesizing the acquired waveforms, interference patterns can be obtained and a cross correlation method is developed to accurately extract the wave velocity as a function of wave frequency. Using three stainless steel thin plates of different thicknesses (100, 150, and 300 μm) and a radius of curvature of 10 mm, dispersion curves for several fundamental and higher order modes of circumferential Lamb waves are simultaneously determined. Theoretical dispersion curves are also calculated and compared with their experimental counterparts. Very good agreements are observed, which concludes the measurement accuracy of this measurement method.

Welding deformation and residual stresses in arc welded lap joints by modified iterative analysis

Welding residual stresses and deformation in arc welded lap joints of thin steel plates were investigated by both numerical simulation and experimental measurement. A modified iterative substructure method was developed for the large deformation problem with locally strong nonlinearity, and the detailed distribution of welding residual stresses was obtained. It was demonstrated that the deformation mode of the top plate is different from that of the bottom plate. The out of plane deformation along the weld line has a convex shape and that along the transverse section has a concave shape. The strength of the base metal has a large influence on the residual stresses. The efficiency and accuracy of the proposed method have been validated by comparing numerical results with experimental results.

Influence of the welding speed on the distortion of thin stainless steel plates—Numerical and experimental investigations in the framework of the food industry machines

This paper concerns the welding of thin plates of machines for the food industry. A 3D finite elements model was developed to analyse the thermomechanical behaviour of 316L steel during the TIG welding process. The objective is the evaluation of the influence of the process parameters (such as the welding speed) on distortions induced by the welding operation. The mobile welding source was represented with a Gaussian profile, whose parameters were calibrated using the response surface of a design of experiments (DOE) method in order to decrease differences between experimental and modelled characteristics of the weld (thickness and width). The change of the reference temperature of the elements that have reached the melting point was found to be an important aspect allowing considering the stress relaxation induced by the material local melting and allowing the prediction of a correct distortion after cooling down. The results are quite realistic and a relative difference of only 5% between measured and calculated values of the welded plate deflection was obtained.

An experimental study on fatigue characteristics of CFRP-steel hybrid laminates

This paper aims to investigate the fatigue characteristics of hybrid laminates consisting of wave carbon fiber reinforced polymer (CFRP) sheets and a thin stainless steel plate under the tension–tension loading. Different loading options (e.g. same stress and same force), layers of CFRP sheets, and lay-ups of laminates (single and double sides) were considered. A series of experimental tests were performed to determine the effectiveness of the CFRP bonding on prolonging fatigue crack initiation life, preventing fatigue crack propagation and extending fatigue life of the hybrid laminates. Three distinct failure modes, classified as delamination, delamination bending and fiber breakage, were observed in the tests. It is shown that the loading conditions and CFRP thickness are the critical parameters affecting the failure modes and fatigue resistance. The crack initiation life and fatigue life of fiber-metal laminates (FMLs) increase by factors ranging from 1.06 to 1.96 and 1.17 to 2.07, respectively, relative to monolithic steel plates under the same force condition; whereas decrease by factors ranging from 0.63 to 0.89 and 0.28 to 0.61 under the same stress condition. Moreover, the double-side bonded FMLs show better fatigue properties and more stable crack propagation than single-side counterpart with the same thickness of CFRP.

Análise numérica da flambagem térmica em placas finas de aço

Placas finas de aço são elementos estruturais muito utilizados em diversas aplicações de engenharia, como em plataformas offshore, pontes, navios, aviões e automóveis. Porém, em algumas situações específicas as placas podem sofrer flambagem térmica, que é uma deflexão lateral causada simplesmente por um aumento de temperatura (variação crítica de temperatura). Este artigo utilizou um modelo computacional desenvolvido no software ANSYS, que é baseado no Método dos Elementos Finitos (MEF), para tratar o problema da flambagem térmica em placas. O modelo numérico foi verificado através da comparação de seus resultados com a solução analítica do problema. Foram analisadas placas com diferentes relações de <em>H</em>/<em>L</em>, sendo <em>H</em> a altura e <em>L</em> o comprimento da placa. Além disso, diferentes espessuras para a placa foram também consideradas. Os resultados indicam que o aumento da variação crítica de temperatura está relacionado tanto ao aumento da relação <em>H</em>/<em>L</em> como também com o aumento da espessura da placa.