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In this paper, a three dimension heat source is developed in laser heated friction stir welding. The model was calculated by CFD software FLUENT, and the temperature field and flow field of the welding are obtained. The effect of absence or presence of laser beam on flow field and temperature field is discussed. The microstructure of nugget zone between laser assisted friction stir welding and traditional friction stir welding is analyzed by metallographic observation. Results show that welding quality will be improved if it is used laser assisted friction stir welding to weld Q235 steel plates instead of traditional friction stir welding. Keywords: Laser-heated, Friction stir welding, Thermal model, Temperature, Microstructure

This work presents results from a numerical investigation on the influence of fluid-structure interaction (FSI) on the dynamic response of thin steel plates subjected to blast loading. The loading was generated by a shock tube test facility designed to expose structures to blast-like loading conditions. The steel plates had an exposed area of 0.3 m × 0.3 m and experienced large deformations during the tests. Numerical simulations were performed using the finite element code EUROPLEXUS. An uncoupled FSI approach was compared to a coupled FSI approach in an attempt to investigate FSI effects. Reduced deformation was observed in the plates due to the occurrence of FSI during the dynamic response. The general trend was an increased FSI effect with increasing blast intensity. The numerical results were finally compared to the experimental data to validate their reliability in terms of deflections and velocities in the steel plates. A good agreement with the experimental data was found, and the numerical simulations were able to predict both the dynamic response of the plate and the pressure distribution in front of the plate with good accuracy. Hence, the numerical framework presented herein could be used to obtain more insight regarding the underlying physics observed in the experiments. The clear conclusion from this study is that FSI can be utilized to mitigate the blast load acting on a flexible, ductile plated structure, resulting in reduced deformations.

The local buckling behaviour and design of stainless steel plates in fire are investigated in this paper. Finite element models of stainless steel plates able to mimic their response in fire are created and validated against experimental results from the literature. Parametric studies are then performed and the results are utilised to assess the current design provisions set out in the European structural steel fire design code EN 1993-1-2; shortcomings in the prediction of the local buckling response of stainless steel plates in fire are revealed. A new effective width based design approach able to reflect the variation in strength and stiffness of stainless steel at different temperature levels in the determination of the local plate slenderness and thereby the ultimate resistances of stainless steel plates in fire is put forward. The proposed approach is shown to provide significantly higher levels of accuracy and reliability relative to the current provisions in EN 1993-1-2 for a wide range of plate slendernesses, elevated temperature levels, stainless steel grades and loading conditions. The design rules proposed for the local buckling assessment of stainless steel plates at elevated temperatures in this paper are due to be incorporated into the upcoming version of the European steel fire design standard EN 1993-1-2.

A comprehensive experimental and numerical study is presented into the behaviour of stainless steel welded I-section beams-columns. Twenty test specimens were fabricated from grade 304 (EN 1.4301) austenitic and grade 2205 (EN 1.4406) duplex stainless steel plates – ten were tested under major axis bending plus compression and ten under minor axis bending plus compression. Material tensile coupon tests and geometric imperfection measurements were also conducted. Numerical models were developed, calibrated against the test results and subsequently employed in parametric studies considering a wider range of specimen geometries. Based on the obtained test and numerical results, the accuracy and reliability of existing design rules given in EN 1993-1-4 and AISC DG 27, as well as recent proposals, were assessed.

Timber joints represent the governing part of a timber structure, particularly when assessing its seismic response. In order to better assess the seismic capacity of traditional timber frame structures, particularly timber-framed shear walls, pull-out and in-plane cyclic tests were carried out on their joints (half-lap joints). The aim is to better understand the influence of the joints on the walls and their influence on failure mechanisms and capacity. Their seismic characterisation was obtained via the analysis of the hysteretic behaviour and dissipative capacity of both unreinforced and retrofitted joints (using self-tapping screws, steel plates and GFRP sheets). Results show that all strengthening techniques were able to improve the dissipative and load-bearing capacity, but care should be taken into not over-stiffening the joints, as it would lead to an overly rigid structure., The first author would also like to acknowledge the Portuguese Science and Technology Foundation (FCT) for its financial support through Grant SFRH/BPD/99891/2014.

Residual stress magnitudes and distributions in structural stainless steel built-up sections have been comprehensively investigated in this study. A total of 18 test specimens were fabricated from hot-rolled stainless steel plates by means of shielded metal arc welding (SMAW). Two grades of stainless steel were considered, namely the austenitic grade EN 1.4301 and the duplex grade EN 1.4462. Using the sectioning method, the test specimens were divided into strips. The residual stresses were then computed by multiplying the strains relieved during sectioning by the measured Young׳s moduli determined from tensile and compressive coupon tests. Residual stress distributions were obtained for 10 I-sections, four square hollow sections (SHS) and four rectangular hollow sections (RHS). Peak tensile residual stresses reached around 80% and 60% of the material 0.2% proof stress for grades EN 1.4301 and EN 1.4462, respectively. Based upon the test data, simplified predictive models for residual stress distributions in stainless steel built-up I-sections and box sections were developed. Following comparisons with other available residual stress test data, the applicability of the proposed models was also extended to other stainless steel alloys. The proposed residual stress patterns are suitable for inclusion in future analytical models and numerical simulations of stainless steel built-up sections.

Publisher Summary A beam comprised solely of concrete has very little bending strength, because the concrete in the tension zone of the beam cracks at very low values of load. Concrete beams are therefore reinforced in their tension zones by steel bars embedded in the concrete. Generally, whether the beam is precast or forms part of a slab/beam structure, the bars are positioned in a mold into which the concrete is poured. On setting, the concrete shrinks and grips the steel bars; the adhesion or bond among the bars and the concrete transmits bending and shear loads from the concrete to the steel. The modern design of reinforced concrete structures relies on the ultimate load theory. The calculated moment of resistance of a beam section is therefore based on the failure strength of concrete in compression and the yield strength of the steel reinforcement in tension modified by suitable factors of safety. Typical values are 1.5 for concrete and 1.15 for steel. However, failure of the concrete in compression could occur suddenly in a reinforced concrete beam, whereas failure of the steel by yielding would be gradual. It is therefore preferable that failure occurs in the reinforcement rather than in the concrete.

This chapter deals with shell plating and framing. The shell plating forms the watertight skin of the ship and at the same time contributes to the longitudinal strength and resists vertical shear forces in merchant ship construction. Internal strengthening of the shell plating may be both transverse and longitudinal and is designed to prevent collapse of the plating under the various loads to which it is subject. The bottom and side shell plating consists of a series of flat and curved steel plates generally of greater length than breadth butt welded together. The side shell plating is maintained within 40% of the vessel's midship length and then tapers to the rule thickness at the ends. The thickness may be increased in regions where high vertical shear stresses occur, usually in way of transverse bulkheads in a vessel permitted to carry heavy cargoes with some holds empty.

Metals are tested to ensure that their strength, ductility, and toughness are suitable for the function they are required to perform. The ship's structure is designed for working stresses that are within the elastic range and much lower than the ultimate tensile strength of the material to allow a reasonable factor of safety. Both mild steel and higher tensile steel plates and sections built into a ship are to be produced at works approved by the appropriate classification society. During production, analyses of the material and prescribed tests of the rolled metal are required. Similar analyses and tests are required by the classification societies for steel forgings and steel castings to maintain an approved quality. Destructive tests are performed on specimens obtained from the same product as the finished material in accordance with the societies' requirements, which may be found in the appropriate rules. These tests usually take the form of tensile tests and impact tests.

This study focuses on the ballistic performances of 1 and 2 mm-thick and 2 × 1 mm-thick cold rolled sheet metal plates against 9 mm standard NATO projectile. The velocity of the projectile before and after perforation, the diameter of the front face deformation, the depth of the crater and the diameter of the hole were measured. The fracture surfaces of the plates near the ballistic limit were also microscopically analyzed. The highest ballistic limit was found in 2 mm-thick plate (332 m s−1) and the lowest in 1 mm-thick plate (97 m s−1). While, the ballistic limit of 2 × 1 mm-thick plate decreased to 306 m s−1. Typical failure mechanism of the projectile was the flattening and mushrooming at relatively low velocities and the separation from the jacket at relatively high velocities. In accord with the ballistic limits, 2 mm-thick target plate exhibited the highest hardness value. Microscopic investigations showed the significant reductions in the grain size of the targets after the test.

Publisher Summary This chapter highlights the design consultancy specializing in agricultural cultivation and crop establishment machinery. As part of a project to design a new concept for a trailer chassis, it is necessary to determine the loadings on and strength/deflections of a conventionally manufactured trailer chassis. Such chassis are generally manufactured from hollow section steel together with flame-cut steel plates and flat bar parts. The requirements of this design problem are to determine: the maximum compressive and tensile stresses in the chassis, the maximum deflection of the chassis under load, the factor of safety, and the key stress zones for potential reinforcement when designing an alternative chassis. The design criteria to be used for this design problem are as follows: material to be used is EN 50D/S355J2G3 steel and factor of safety required is 1.5.

Airborne velocities and deposition fluxes (DF) of NO3−1 and SO4−2 on various surrogate surfaces, specifically petridishes of polypropylene and glass, marble slabs, ceramic tiles, and stainless steel plates, were measured between January and June, 1991. DFs were higher in the summer months, but varied with the surface, decreasing in the order above. In the summer, NO3−1 DFs were higher than corresponding SO4−2 values. In the winter, this trend was reversed. Deposition velocities of both species were of the order of 10−3cm s−1.

Worldwide, a great deal of research is currently being conducted concerning the use of fibre reinforced plastic wraps or laminates in the repair and strengthening of reinforced concrete members. Such techniques can be both effective and economical when compared to the existing practice of retrofitting with steel plates. A novel technique which further simplifies the application procedure is to apply the fibre using a spraying process. By spraying the fibres onto the member surface concurrently with a suitable matrix resin a two dimensional random distribution of discontinuous fibres is obtained, resulting in an FRP plate that exhibits isotropic in-plane behaviour.

Thin steel plates, which have initial cracks at the center, are used as the Sacrificial Test Pieces in this study. “The Sacrificial Test Piece” is attached to the member of a main structure in order to evaluate the damage before the appearance of a crack in the member of the main structure. The purpose is to show the practical applicability of “the thin steel plate with crack as the Sacrificial Test Piece” for monitoring the fatigue damage parameters on bridge members. In this research, it is decided that the applicable range of crack length and the crack propagation properties of the Sacrificial Test Pieces to evaluate the fatigue damage parameter are obtained. And it is suggested that the fatigue damage parameter can be estimated by the Sacrificial Test Pieces with practical accuracy by the test under constant amplitude loading.

In the previous research the minimum cost design of the uniaxially compressed orthogonally stiffened welded steel plate has been worked out. Based on this result the cost minimization of a cantilever stub column of square box cross section with orthogonally stiffened side plates is formulated and solved. The constraints relate to the overall and stiffener torsional buckling of side plates and to the horizontal displacement of the column top due to a horizontal force. Halved rolled 1-section stiffeners are used in both directions. The cost function includes the cost of material, assembly, welding and painting. The variables are the thickness and width of the side plates as well as the dimensions and numbers of stiffeners in both directions. The optimization is performed using the particle swarm algorithm.

Publisher Summary This chapter deals with shell plating and framing. The shell plating forms the watertight skin of the ship and at the same time contributes to the longitudinal strength and resists vertical shear forces in merchant ship construction. Internal strengthening of the shell plating may be both transverse and longitudinal and is designed to prevent collapse of the plating under the various loads to which it is subject. The bottom and side shell plating consists of a series of flat and curved steel plates generally of greater length than breadth butt welded together. The side shell plating is maintained within 40% of the vessel's midship length and then tapers to the rule thickness at the ends. The thickness may be increased in regions where high vertical shear stresses occur, usually in way of transverse bulkheads in a vessel permitted to carry heavy cargoes with some holds empty.

Publisher Summary Metals are tested to ensure that their strength, ductility, and toughness are suitable for the function they are required to perform. The ship's structure is designed for working stresses that are within the elastic range and much lower than the ultimate tensile strength of the material to allow a reasonable factor of safety. Both mild steel and higher tensile steel plates and sections built into a ship are to be produced at works approved by the appropriate classification society. During production, analyses of the material and prescribed tests of the rolled metal are required. Similar analyses and tests are required by the classification societies for steel forgings and steel castings to maintain an approved quality. Destructive tests are performed on specimens obtained from the same product as the finished material in accordance with the societies' requirements, which may be found in the appropriate rules. These tests usually take the form of tensile tests and impact tests.

Publisher Summary The chapter explores a numerical study on the fatigue repair of structural steel using stop hole related techniques. When subjecting cyclic loading, structural steel may suffer from fatigue cracking. Cracks always initiate at the locations of stress concentration and may propagate until a fracture occurs. Stop hole method is a commonly used fatigue repair method for thickness cracks on steel plates, in which a hole is drilled at the crack tip to eliminate the stress concentration and stop the crack propagation. The effectiveness of this method can be improved by using a cold expanded hole and inserting interference fit fasteners. The mechanism of stop hole related techniques is numerically studied in the chapter. The stress and strain states around the stop hole of different techniques are determined by elastic-plastic finite element analysis, based on which the effectiveness of these techniques is compared in the chapter.

Publisher Summary In order to possess the ductility of thin-walled steel structures, the high performance steels whose material properties can be controlled may practically be used in lieu of the ordinary steels. In this chapter, the elasto-plastic finite displacement analyses are carried out for uniaxial compressed steel rectangular plate with initial imperfections of deflection and residual stress. The inelastic behavior on the ultimate state and thereafter of these steel plates with various aspect ratios and width-thickness ratios are parametrically examined for the yield plateau length and the strain-hardening gradient. The influences of both the parameters on ductility are discussed from many analytical results. It follows that their two material properties are opportunely controlled for possessing ductility of uniaxial compressed rectangular steel plates. Additionally, the required values of their parameters (the yield plateau length and the strain-hardening gradient) are cleared by the illustrations in order to efficiently possess the ductility of rectangular steel plates. In this study, the inelastic behavior of the high performance steel plates under uniaxial compression is parametrically examined by elastoplastic finite displacement analyses. It is found that the high performance steel can effectively possess the ductility of the rectangular plates under compression by controlling the material properties, the yield plateau length, and strain hardening gradient.

The development of numerical models for analysing stainless steel plates in compression are described in the paper. Included are material tests on coupons cut in the longitudinal, transverse and diagonal directions along with the results of stainless steel plates. The paper makes detailed comparisons between the experimental and numerical ultimate loads and load displacement curves. Results show that excellent agreement can be achieved by using the compressive stress strain curve pertaining to the longitudinal direction of loading.. Also investigated is the effect of anisotropy using elastic-perfectly-plastic material models where the anisotropic material model is based on Hill's theory. These model show that the effect of anisotropy is small and that it may not be required to account for anisotropy in the modelling of stainless steel plates in compression.

Publisher Summary This chapter discusses a series of experimental results and numerical predictions, using the finite element package ABAQUS, on built-in mild steel plates of different stiffener configurations subjected to a uniform blast load. The quadrangular plates are 1.6 mm thick with stiffener size of 3 x 3 mm, 3 x 7 mm, 4 x 3 mm, and 4 x 7 mm in configurations of single, double, cross, and double cross stiffeners. The impulse required to give deformations up to plate tearing is obtained by the explosive, centrally laid out in two concentric rectangular annuli. Observations show that in all the tests, where tearing does not occur regardless of the size and configuration of the stiffeners, the plate profiles are characterized by a uniform global dome. Thinning mechanisms at the boundary are observed for all plates in spite of different stiffener sizes and configurations. Thinning, however, is not consistent all around the boundary. Tearing is observed to first occur at the middle of the sides of the plates and then progresses toward the corners as the impulse increases. The numerical predictions that incorporate non-linear geometry and material effects, including strain rate sensitivity and temperature effects, show an encouraging correlation with experimental data for both the displacement profile and tearing.

Recycling steel cans instead of making new products uses so much less energy, pollution, water and water pollution. In Japan in 1994 about 472,000 tons of steel cans could not be recycled. It meant a huge amount of steel plates could be reused as steel fibers to reinforce plain concrete by considering many advantages of fibrous concrete. Reusing of waste steel cans as a construction material in plain concrete can improve concrete properties and also protect corrosion of reinforced concrete. In this matter behaviour of steel fibers made from steel cans in a transparent gel and concrete specimens were studied. Results of experiments showed that such fibers with average thickness of 0.25 mm increase flexural strength of plain concrete about 150%. Durability of these fibers under an accelerated and artificial aggressive environment showed that more than 75% of fibers in the concrete matrix were sound. However, such fibers in contact with steel bars could cathodically protect corrosion of steel bars. (A) For the covering abstract see ITRD E121685.

The curvature of carbon and 304 stainless steel thin plates in surface grinding has been studied using white alumina, CBN, and diamond wheels. The grinding experiments were carried out on the workpiece, whose size was 1.5mm thickness and 100mm length. Grinding force, as well as residual stress, and grinding affected zone were measured. Thus, the difference in curvature for the WA, CBN, and diamond wheels was evident. The influences of up-cut, down-cut, and multi-pass grinding on curvature and the curvature in grinding wide plates were also investigated. Moreover, the factors such as, grinding heat, burnishing effect, quenching, and transformation were discussed, and also, the mechanism of curvature was suggested.

Al2O3 layers are used to reduce electromagnetic forces on ICRH antenna parts during disruptions. The layers are plasma sprayed on stainless steel plates, and act as high pass filter capacitances. Their design, manufacturing and characteristics are described.

The present paper will describe the research activities for modelling of micro-structural evolution and properties of steel products. An integrated model in which the metallurgical phenomena and mechanical properties of steel plates produced by Thermo–mechanical control process are calculated will be introduced as the most advanced example. This model is in operation as a part of quality design system of commercial production line after the examination with a wide range of experimental data. Research for expanding applicable products and processes and for improving accuracy is in progress. Monte Carlo simulation for describing inhomogeneity of microstructures is being developed as an advanced modelling technique.

The FST is a new type of cylindrical convergent HE device which creates well behaved gases with energy levels far above those possible with conventional HE systems. At the present time we have a well developed FST which creates high energy gases with a density of over 2 gm/cc, a particle velocity above 6 km/sec, and free expansion velocities of approximately 20 km/sec. These gases have been used to accelerate stainless steel plates to over 10 km/sec. The pressures created in the plates during acceleration exceed 1 Mbar. Development is proceeding on an advanced system to create gases with 2.5 times the energy levels of the present one. This paper discusses the principles behind the successful operation of the FST, describes the present system, and discusses the advanced system.

The fatigue test and the ultrasonic measurement of diffusion bonded steel plates were done. The bonded specimen was classified into two groups by a size of a bonded region estimated with the ultrasonic measurement, and the specimen classified into good bonding had a longer life than that classified into bad bonding. The fatigue limit was 20 MPa in stress amplitude, and was about 20 % of the static shear strength.

Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed.

Eddy current impedance imaging (ECII) is a recently emerging trend in the area of non-destructive testing. Compared to conventional eddy current testing (ECT), ECII gives a global perspective and allows a balanced interpretation. Imaging techniques have the potential of automating the measurement process and providing estimates of defect size from the image data. This paper describes the work carried out at the authors' laboratory with respect to development of the ECII technique as a tool for in-service inspection of welds. Details of the ECII system, implications of probe characteristics and some relevant applications to weld joints are presented.

The interaction of Lamb waves with crack-like defects in steel plates has been investigated both numerically and experimentally. Excellent agreement between the predicted and measured transmission ratios has been obtained and it has been shown that Lamb waves may be used to detect defects when the ratio of wavelength to defect depth is as high as 40.

A computational model for predicting microstructural changes at any stage of manufacturing by Thermo-Mechanical Control Process and mechanical properties of heavy steel plates has been developed. Optimum combination of chemical composition and process conditions can be calculated by using this model.

The primary objective of this investigation was to make experimental measurements of stress and strain levels at various depths along the line of penetration in steel plates during long rod impact. Strain levels in the targets affected the stress gauge measurements. A new technique was used to reduce the stress record that allowed for this effect. Thus, the strain-compensated stress records were obtained along with strain histories for four tests. This work forms a base for the better understanding of some aspects of long rod penetration.

The rapid development of adhesively bonded joints has pointed up the need for an adequate joint analysis and design. The analysis of single lap joint shows stress concentration at the joint ends due to the eccentricity of load direction. The maximum stresses can be reduced by several changes in the metal members of the joint. One of the vital changes is to increase the thickness of the joint by stepwise procedure interposing a thin plate between two stiff members of the single lap joint. The improved joints were analyzed using the finite element technique. The theoretical prediction was verified experimentally by bonding two steel plates and different intermediate plates. Extensive study was directed towards investigating the influence of different parameters which may affect the joint strengths criterion describing the major parameters which affect the design of the optimum joint was developed and found to be consistent with experimental results.

This paper is a study of a manufacturing procedure and the characteristics of steel plates (maximum thickness 100mm, YP>355N/mm 2 , TS>480–490N/mm 2 , service temperature −10 −50 °C class) designed for arctic service. As ocean development becomes more active, the properties required for steel plates become increasingly severe. To satisfy these requirements, a steel manufacturing technology capable of meeting the needs of users who demand high-quality products and ease of welding and fabrication has been developed. This new technology has made possible the manufacture of extra heavy plates (maximum thickness of 100 mm).

This paper describes the cooling equipment and control system of the thermo-mechanical control process (TMCP) developed by Nippon Steel. Nippon Steel started the research and development of the cooling equipment and control system in 1978 and shipped the first product manufactured by the TMCP in February 1983. The cooling equipment is located at the rear of the hot leveller, is of the closed type, employs the continuous cooling method, performs accelerated cooling and direct quenching in combination over a wide control range of cooling rates and is provided with a computer-aided cooling rate and flatness control system. It is installed at all plate mills of Nippon Steel, where a total of 1,000,000 tons of steel plates have been produced by the new process since February 1983.

This paper describes an experimental method for determining the through-thickness distribution of residual stresses in flat plate samples. The technique involves material removal from one surface by chemical etching. With strain gauges attached to the opposite surface of the sample, strains are monitored throughout the test sequence. The distribution of through-thickness residual stresses is determined using appropriate equations. The technique has been evaluated by tests on: a) Heat-treated stress-free bars, and b) Initially stress-free bars subjected to four-point bending beyond the elastic limit. The results are satisfactory and indicate that the layer removal method may be adequately used for the evaluation of residual stresses in a number of practical applications.

Angle beam ultrasonic testing has been applied to the steel weld based on isotropy of steel. However, in the test of textured steel, the problems arise sometimes in detectability and location estimation of flaws. These problems are considered to be a result of acoustical anisotropy of material. Many researchers have investigated the ultrasonic characteristics in the anisotropic media. The present work reports the acoustical anisotropy of textured steel plates, and ultrasonic characteristics of the anisotropic steel plates. The effects of anisotropy on the angle beam ultrasonic test are discussed. As a result, an effective ultrasonic testing method of textured steel was developed and applied to weld specimens of anisotropic steel plates. It was made clear that the method was effective for detection of weld flaws in steels.

Publisher Summary This chapter describes requirements and standards for steel vertical cylindrical storage tanks. Crude oil and oil products for the petroleum industry are generally stored in steel vertical cylindrical tanks with flat bottoms. The tanks can be divided into two main groups: (1) fixed-roof tanks and (2) floating-roof tanks. Two different types of roof are necessary to enable adequate reduction of vapor losses for the various types of oil. A fixed roof consists of steel plates resting on a supporting framework and attached to the tank only at the top of the shell. A floating roof is a steel disc that floats on the surface of the oil and rises or falls with the oil levels as the tank is filled or emptied. In a fixed-roof tank, the space between the oil and the roof is filled with vapor. Owing to the presence of this vapor space, evaporation losses from breathing and filling occur during use.