Nonlinear Analyses Of Steel Plates Submitted To Axial Compression Forces Considering Residual Stresses

Author(s):  
Elvys Reis ◽  
Caroline Martins Calisto ◽  
Ana Lydia Castro e Silva ◽  
hermes carvalho
1989 ◽  
Vol 111 (1) ◽  
pp. 71-73 ◽  
Author(s):  
M. O. Lai ◽  
A. Y. C. Nee

This investigation examines the effects of different finishing processes on the fatigue life of premachined holes in Assab 760 steel plates. The finishing processes studied were reaming, ballizing, and emery polishing. A general decrease in fatigue life with increase in surface roughness is observed for all the processes employed. In comparing the different processes, for a constant surface roughness, polishing is generally found to give the longest fatigue life while ballizing, in spite of the greater compressive residual stresses induced on the surface of the finished hole, the shortest. The surprising phenomenon was found to be attributed to the amount of plastic deformation occurred before fatigue loading. For Assab 760 steel, a prestrain in the radial direction of less than about 2.5 percent appeared to reduce the fatigue resistance of the material.


2020 ◽  
Vol 8 (9) ◽  
pp. 702
Author(s):  
José Manuel Gordo

A robust methodology to simulate virtually the residual stresses pattern in welded steel plates is presented. The methodology is applied to the structural analysis of typical welded plates belonging to ship structures, and the effect of residual stresses on the elastoplastic behavior of plates loaded axially is analyzed in comparison to the residual stress free case, both for tension and compression and including initial imperfections. Residual stresses affect in different manner plates with different geometries; thus a parametric study is performed covering the usual range of variation of the most important plate parameters that control the strength of the plates, more precisely the slenderness and the aspect ratio. The results from finite elements analysis are compared with codes and most established formulations and recommendations of applicability in the prediction of load-shortening curves for hull’s bending strength evaluation, ultimate strength and ultimate strain of plate elements are made.


2014 ◽  
Vol 996 ◽  
pp. 755-760 ◽  
Author(s):  
Bilal Ahmad ◽  
Michael E. Fitzpatrick

Fatigue cracks mostly initiate at areas subjected to high tensile residual stress and stress concentration. Ultrasonic peening is a mechanical method to increase fatigue life by imparting compressive residual stress. In this study residual stresses are characterized in fillet welded ship structural steel plates with longitudinal attachments. As-welded, ultrasonically peened, and specimens peened then subjected to accelerated corrosion testing were measured. Residual stress characterization was performed by the contour method and neutron diffraction.


2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Hua Huang ◽  
Kailin Xi ◽  
Yu Zhang ◽  
Jinghui Shi ◽  
Boquan Liu

The load carrying capacity and failure mechanism of 8 square columns strengthened with high-performance ferrocement laminate (HPFL) and bonded steel plates (BSP) were analyzed on the basis of experiments on the axial compression performance of these columns. Results show that the reinforcing layer worked together with the original columns as a whole, and the load-bearing capacity significantly increased. When failure of the strengthened column occurred, the mortar and concrete were crushed and bulged outward in the middle of the columns, the angle bars and longitudinal steel bars buckled, and some stirrups were pulled out. The chamfering of angle bar momentously affected the primary damage of steel strand. The values of the strength reduction factor and pressure effective utilization coefficient of the mortar were suggested. Based on the experiments and existing tests of 35 columns strengthened with HPFL, equations for the axial compression bearing capacity were proposed and all calculation results agreed well with testing results. Therefore, the calculation method could be used in the capacity design of axial compression strengthened columns.


2017 ◽  
Vol 267 ◽  
pp. 212-218 ◽  
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Eron Adoberg ◽  
Liina Lind ◽  
...  

The aim of the study was to determine macroscopic residual stresses in Physical Vapor Deposits (PVD) coatings through measurement of the length variation of the strip substrates coated on both sides. The length change of the strip was reduced to the deflection of the middle cross-section of the elastic element and was recorded by four strain gauges. For validating the obtained results, the conventional curvature method was used. As an application, residual stresses in hard AlCrN PVD coatings were investigated. The coatings were nanolayered to achieve better coating toughness for blanking and punching applications. The steel strips and steel plates with two thicknesses were used as the substrate. The values of the compressive residual stresses, determined by both methods for the investigated coatings, were very high (3.3 -3.6 GPa) independent of coating thickness and practically equal within the measurement uncertainty of the method. Good agreement between the experimental results obtained with both methods suggests that the presented method, strip length variation, is applicable for determination of residual stresses in coatings. Compressive stresses in coatings are desirable as they strengthen the coating.


2018 ◽  
Vol 941 ◽  
pp. 269-273
Author(s):  
Constant Ramard ◽  
Denis Carron ◽  
Philippe Pilvin ◽  
Florent Bridier

Multipass arc welding is commonly used for thick plates assemblies in shipbuilding. Sever thermal cycles induced by the process generate inhomogeneous plastic deformation and residual stresses. Metallurgical transformations contribute at each pass to the residual stress evolution. Since residual stresses can be detrimental to the performance of the welded product, their estimation is essential and numerical modelling is useful to predict them. Finite element analysis of multipass welding of a high strength steel is achieved with a special emphasis on mechanical and metallurgical effects on residual stress. A welding mock-up was specially designed for experimental measurements of in-depth residual stresses using contour method and deep hole drilling and to provide a simplified case for simulation. The computed results are discussed through a comparison with experimental measurements.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Bin Huang ◽  
Zhou Che Hong

Finite element models (FE models) of high-strength steel Q420 (yield strength 420 MPa) circular tubes considering residual stresses and local and overall geometric imperfections were established and verified against existing test data. Based on parameter analysis, it was derived that the reduction of ultimate capacity resulting from residual stresses was up to 11.8%. When slenderness ratio was larger than 25, the effect of overall geometric imperfection played a major role compared with that of local geometric imperfection, which resulted in the reduction of the ultimate capacity of about 11.5%. Through tracking the failure process, it was found that, in the initial stage of loading, the deformation of columns mainly presents overall bending. When the load increased near the ultimate load, local buckling occurred and the bearing capacity decreased rapidly. The D/t limit value 27 was determined for preventing the local buckling, and the overall slenderness λl limit value 40 was proposed to distinguish whether local buckling occurs. Based on the FEM result and test data, the applicability of ASCE48-05 and AS4100 for local buckling resistance was evaluated. Continuing the result of stub columns, curve a in GB50017-2017 and in Eurocode 3 of the overall buckling factor φ was proposed to be used in EWM and DSM for estimating the interactive buckling resistance of circular tubes of Q420 under axial compression.


2020 ◽  
Vol 205 ◽  
pp. 110097 ◽  
Author(s):  
Hong-Song Hu ◽  
Peng-Peng Fang ◽  
Yang Liu ◽  
Zi-Xiong Guo ◽  
Bahram M. Shahrooz

Author(s):  
C. Hakan Gür ◽  
Gökhan Erian ◽  
Caner Batıgün ◽  
İbrahim Çam

Variations of surface residual stresses as a function of weld runs in API 5L X70 steel plates were non-destructively monitored by Magnetic Barkhausen Noise (MBN) method. After each weld run, MBN signal and hardness distributions were recorded. MBN signals were converted into stress values by using a specific calibration procedure. The results were analyzed by considering microstructure investigations and hardness measurements, and then, they were compared with the results of X-ray diffraction measurements. MBN method seems to be a good candidate for monitoring the variation of surface residual stresses. It may also provide critical data for computer simulation and process design of welding processes.


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