Review of European design provisions for buckling of aluminium members with longitudinal welds – part 1

Stahlbau ◽  
2022 ◽  
Vol 91 (1) ◽  
pp. 19-19
Keyword(s):  
Longitudinal Welds

scholarly journals Analysis of Ultimate Load-Carrying Capacity of Combined Connection with Bolts and Welds

Mechanika ◽  
2019 ◽  
Vol 25 (6) ◽  
pp. 426-433 ◽  
Author(s):  
Tao LAN
Keyword(s):  
Ultimate Load ◽  
High Strength ◽  
Shear Plane ◽  
Deformation Capacity ◽  
Load Carrying Capacity ◽  
Element Calculation ◽  
Lap Splices ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Longitudinal Welds

In this paper, load-carrying and deformation capacity of tension lap splices that have both welds and bolts acting in the same shear plane are studied using numerical method. The failure criterion of bolts and welds are given based on the finite element calculation and compared with existing experiment results, it shows that the established numerical model is correct and reliable. The strength of longitudinal welds and the bearing capacity of the high-strength bolts before slipping can be fully used in the combined joints, the bolts and welds fail almost simultaneously. The deformation of welds in combined connections is less uniform than its’ deformation in welded joints as the welds fails, and it causes the deformation of welds as failure is larger in combined connections than in welded connections. The deformation capacity of the combined joint are slightly increased contrasted with bolts joint and welds joint because of the interplay of bolts and welds acting in the same shear plane. The strengths of welds and bolts performed in combined connections can reach 0.95 and the deformation of combined connection is increased at least 1.10 times as the welds connection or the bolts connection.

BEHAVIORS OF SLIP-CRITICAL BOLTS IN COMBINATION WITH FILLET WELDS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Heui-Yung Chang ◽  
Ching-Yu Yeh ◽  
Chia-Yu Chen
Keyword(s):  
Structural Steel ◽  
Fracture Strength ◽  
Fillet Welds ◽  
Strength Ratio ◽  
Steel Buildings ◽  
Bearing Strength ◽  
Fracture Surfaces ◽  
Weld Material ◽  
Transverse Welds ◽  
Longitudinal Welds

According to the Specification for Structural Steel Buildings (AISC 2010), slip-critical bolts can only share load with longitudinal welds in a joint. Moreover, the bolt available strength shall not be taken greater than 50% of the bearing-type. This paper presents the result of a series of joint tests verifying the specification. The joints were tested in a manner similar to previous work (e.g. Manuel and Kulak 2000). The slip strength values of JIS F10T and F14T bolts were tested and compared. Transverse and longitudinal fillet welds with a leg size of 12 mm and the same amount of weld material were adopted and tested respectively. The strength ratio between bolts and welds changes from 5/8 to 6/9 in the combination joints. The result shows that in the combination with longitudinal welds, the bolts tend to slip and contact the plates, developing greater bearing strength. In the combination with transverse welds, the bolts slip and the pretension decreases greatly. But the combination also causes the fracture surfaces of transverse welds to change, providing additional strength to compensate the decrease in bolt slip strength. The combination joints therefore can develop strength greater than the sum of slip strength and fracture strength.

Production of Metallurgically Cladded Pipes for High End Applications in the Oil and Gas Industry

2008 ◽  
Author(s):  
Thilo Reichel ◽  
Jochem Beissel ◽  
Vitaliy Pavlyk ◽  
Gernot Heigl
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Oil And Gas ◽  
Fem Analysis ◽  
Oil And Gas Industry ◽  
High Corrosion Resistance ◽  
Gas Industry ◽  
High Corrosion ◽  
Manufacturing Procedure ◽  
Longitudinal Welds

The paper describes the different industrially used options to produce a clad pipe and explains in detail the manufacture of metallurgically cladded pipes starting with the production of roll bonded plates. In plate manufacturing the advantages as well as the limitations of thermo-mechanical (TM) rolling are discussed. The TM-technology is shown to improve weldability, HIC-resistance, strength and toughness properties of the carbon steel section of the pipe. Moreover, it also improves corrosion resistance of the CRA layer. The pipe manufacturing procedure, which involves two welding technologies for longitudinal welds is described. The carbon steel parts of the pipe are joined using double-sided multi-pass Submerged-Arc-Welding (SAW). The single-pass Electroslag-Welding (ESW) is subsequently used for recladding of the CRA layer. The multi-pass SAW results in excellent mechanical properties of the weld joint, whereas the ESW technique ensures low dilution of CRA with the carbon steel, a smooth weld bead shape and a high corrosion resistance of the deposited layer. With the aid of thermodynamic modeling and numerical simulations it is shown, that the high corrosion resistance is promoted by an intensive mixing within the ESW weld pool and relatively low segregation level of Cr and Mo during solidification. Furthermore, FEM analysis is applied to examine the plastic deformation and residual stresses distribution in the pipe during forming, welding and final calibration. The obtained information assists in optimization of manufacturing procedure, and can also be included in prediction of resulting pipe fatigue during operation.

The Effect of Hoop Stress on the Burnthrough Susceptibility During In-Service Welding of Thin-Walled Pipelines

2008 ◽  
Author(s):  
Matthew A. Boring ◽  
William A. Bruce
Keyword(s):  
Failure Mechanism ◽  
Wall Thickness ◽  
Hoop Stress ◽  
Pipe Diameter ◽  
Welding Parameters ◽  
Minor Effect ◽  
Circumferential Welds ◽  
Welding Arc ◽  
Thin Walled ◽  
Longitudinal Welds

Most companies control the risk of burnthrough by prohibiting welding on pipelines with wall thicknesses below a specified thickness. This is a safe approach but the risk of burnthrough depends not only on the wall thickness, but also on the welding parameters and the operating parameters of the pipeline which include pressure. It is generally acknowledged that the hoop stress caused by pressurizing the pipeline has a relatively minor effect on the risk of burnthrough since the size of the area heated by the welding arc is small. While this has certainly been shown to be true for thicker materials, previous research has shown that the pressure can have a dramatic effect on burnthrough risk for thinner materials. The objective of this project was to further investigate the effects pressure and hoop stress has on the burnthrough risk of welding onto thin-walled pipelines in service. For circumferential welds, pressure and wall thickness determine the burnthrough risk and pipe diameter appears to have no effect. The failure mechanism for circumferential welds is consistently a burnthrough. For longitudinal welds, pipe diameter does appear to affect burnthrough risk even though the effect appears to be secondary to pressure and wall thickness. The pipe diameter is believed to be more influential for longitudinal welds because of the larger area of heated material that is exposed to the hoop stress. Also, the results indicate that the magnitude of the hoop stress has a direct effect on the failure mechanism for longitudinal welds (i.e., burnthrough or weld centerline cracks). For longitudinal welds, the failure mechanism is commonly burnthrough for welds made onto pipes with a hoop stress below 30% specified minimum yield stress (SMYS) which indicates that the internal pressure of the pipe is the main driving force for failure. Longitudinal welds made on pipes which are experiencing hoop stress above 30% SMYS commonly fail by weld cracking. It is important to note that even though pressure does have an effect on the burnthrough susceptibility of welds made on thin-walled pipelines, pressure only becomes a factor for welds made at heat input levels in excess of what is predicted safe by thermal analysis modeling.

scholarly journals INITIATION AND PROPAGATION OF FATIGUE CRACKS IN PARTIALLY-PENETRATED LONGITUDINAL WELDS

1981 ◽  
Vol 1981 (312) ◽  
pp. 129-140
Author(s):  
Chitoshi MIKI ◽  
Fumio NISHINO ◽  
Jiro TAJIMA ◽  
Yoshitaka KISHIMOTO
Keyword(s):  
Fatigue Cracks ◽  
Initiation And Propagation ◽  
Longitudinal Welds

Tensile Plastic Instability of Axisymmetric Pressure Vessels

1998 ◽  
Vol 120 (1) ◽  
pp. 6-11 ◽  
Author(s):  
D. P. Updike ◽  
A. Kalnins
Keyword(s):  
Pressure Vessel ◽  
Detrimental Effect ◽  
Cylindrical Shells ◽  
Plastic Instability ◽  
Pressure Vessels ◽  
Reduction Factor ◽  
Test Results ◽  
Strength Reduction Factor ◽  
Burst Data ◽  
Longitudinal Welds

This paper examines the calculated pressure at a tensile plastic instability of a pressure vessel and its relationship to burst test results. It is proposed that the instability pressure be accepted as an upper bound to the pressure at which a vessel bursts, and that a strength reduction factor be used to predict the burst. The paper also presents a suitable mathematical model for the calculation of the instability pressures for thin-walled axisymmetric vessels. The proposition is tested by applying the model to a pressurized diaphragm, four cylindrical shells, and two torispherical heads, for which experimental burst data are available. It is found that the ratio of the test burst pressure to the calculated pressure at the tensile plastic instability, expressed in percent, ranges from 71 to 96 percent. The highest ratio occurs for a pressurized diaphragm with no significant defects. The lowest ratios occur for cylindrical shells with longitudinal welds, suggesting that the presence of the welds had a detrimental effect on the burst strength. These results may be useful when designing a pressure vessel with respect to its ultimate strength.

Inspection Case Analysis of Natural Gas Manifold in a High Acid Gas Field

2020 ◽  
Author(s):  
Jielu Wang ◽  
Wenming Song ◽  
Xiaoying Tang ◽  
Ju Ding ◽  
Zhe Pu
Keyword(s):  
Natural Gas ◽  
Great Influence ◽  
Case Analysis ◽  
Test Results ◽  
Safe Operation ◽  
Gas Field ◽  
Manufacturing Defects ◽  
Acid Gas ◽  
High Acid ◽  
Longitudinal Welds

Abstract Natural gas manifold is one of the key production facilities in gas field. It is used to buffer, collect and distribute natural gas in natural gas station. In the gas gathering terminal station of a high acid gas field, one of the manifolds had cracks and leakage on the surface of longitudinal welds when it ran for less than 100 hours. Several tests had been carried out of the failure weld seam. Test results analyses and theoretical analysis show that the cracking may cause by weld defects and propagated rapidly based on the mechanism of hydrogen blisters and HIC. In order to verify the conclusion of the analyses and ensure the safe operation of the gas field, an overall inspection of all the natural gas manifolds in the gas field had been carried out. The inspection results proved that there were manufacturing defects in the weld of all the manifolds in this gas field. The natural gas manifold has great influence on the safe operation of natural gas field. The poor working condition of the manifold may lead to failure and even endanger the safety of production. The case analysis in this paper provides a reference for the manifold inspection and ensures the safe operation of the gas field.

scholarly journals Bending Strength of Welded Joints in TMCP Steel Square Tubular Profiles “T” Connexions

2016 ◽  
Vol 5 (3) ◽  
pp. 70
Author(s):  
Rafael Luciano Dalcin ◽  
Ivan Guerra Machado ◽  
Arnaldo Ruben Gonzalez ◽  
Cintia Cristiane Petry Mazzaferro
Keyword(s):  
Tensile Strength ◽  
Welded Joints ◽  
Bending Strength ◽  
Mechanical Efficiency ◽  
Structural Steels ◽  
Detailed Data ◽  
Welded Structures ◽  
Longitudinal Joints ◽  
Longitudinal Welds ◽  
Loading Axis

The use of DOMEX 700 MCTM steel weldments is still little explored, due to some concern of the validity of the rules imposed by several standards and Codes for this class of steel. This material has low ductility and consequently the relation between tensile strength and yield strength is significantly lower than ordinary structural steels. For this reason, the instability phenomena are more critical than the instability phenomena of ordinary structural steels. Therefore, the aim of this study was to obtain detailed data on the mechanical efficiency of joints welded by GMAW. Six different heat inputs were used on square tubular profiles of TMCP steel. The tubular profiles were placed as a column/beam weldment with transverse and longitudinal welds positioned in relation to the loading axis. Twelve welded structures were instrumented with extensometer and tested in simple bending. Comparing the obtained data, it was verified that longitudinal welded joints presented higher bending strength than transversal welded joints. In the case of longitudinal joints, two weld beads were subjected to bending efforts, and in the case of transverse joints, only one weld bead resisted bending forces.

Review of European design provisions for buckling of aluminium members with longitudinal welds – part 3

2021 ◽  
Author(s):  
Thomas Misiek ◽  
Bert Norlin ◽  
Reinhold Gitter ◽  
Torsten Höglund
Keyword(s):  
Longitudinal Welds

Repair Technology for Single Deck Distortion of Floating Roof Tank

2008 ◽  
Author(s):  
Hongli Pan ◽  
Ping He ◽  
Guangzhong Liu
Keyword(s):  
Local Stress ◽  
Construction Process ◽  
Nondestructive Examination ◽  
Technical Requirements ◽  
Assembly Method ◽  
Small Distortion ◽  
Transverse Welds ◽  
Welding Procedure ◽  
Longitudinal Welds ◽  
Sequential Assembly

The repair welding procedure and assembly method that is considered as the key of repair single deck distortion are pointed out in this paper. Also presented is the repair plan of single deck distortion which consists of four stages: stress release, distortion repair, stress adjusting, and sequential assembly. The steps and technical requirements of repair single deck distortion are as follows: Step 1: Installing repairing platform — The platform should have enough stiffness, or else it will influence the repair effect of single deck distortion. Step 2: Inspecting the stress and distortion of single deck plates — The intention of inspecting the stress and distortion of single deck plates is in order to select the welds which should be retained or removed, and to confirm the sequence of removing the welds. The method of lattice is applied in inspection. Step 3: Removing single deck plates — The principle of removing single deck plates is to remove longitudinal welds and adjust the longitudinal distortion of single deck plates first, then removing transverse welds and adjust the transverse distortion of single deck plates. Step 4: Eliminating the local stress of single deck — The key of eliminating local stress of single deck is to control the skill of releveling the single deck plates, assembly of shaped single deck plates, dot welding of single deck plates and inspecting the distortion of the single deck plates. Step 5: Eliminating the integral stress of single deck — The single deck is divided into nine parts. Small distortion of single deck is eliminated first, then the serious distortion. Step 6: Adjusting the distortion of assembled single deck plates — Adjusting the distortion of assembled single deck is a very important process for single deck repair. The adjusting method is from integral to local and then from local to integral of single deck repeatedly. Step 7: Welding single deck plates — The step is to weld short welds first, then long welds. From the center to all sides of single deck, the method of skip welding is applied. Step 8: Nondestructive examination — All welds should be examined in accordance with relevant standards. This technology can eliminate 98% of single deck distortion, which can eliminate the sinking risk of floating roof. The technical requirements of construction process developed in this paper can also be used to instruct the construction of the new floating roof tank’s single deck. The construction process helps to reduce the initial distortion of single deck.

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