Development of a Methodology for Model Testing of Utor Welded Joints of a Vertical Cylindrical Tank

2021 ◽  
pp. 21-27
Author(s):  
D.A. Neganov ◽  
◽  
A.E. Zorin ◽  
O.I. Kolesnikov ◽  
G.V. Nesterov ◽  
...  
Keyword(s):  
Welded Joints ◽  
Strain State ◽  
Welded Joint ◽  
Design Parameters ◽  
Cylindrical Tank ◽  
Stress Strain ◽  
The Real ◽  
Stress Strain State ◽  
Hydraulic Machines ◽  
Wide Range

The methodology of laboratory modeling of the loading of utor welded joint of the tank is presented. The methodology is based on testing of the special design sample. It allows under uniaxial tension on the typical servo-hydraulic machines to reproduce in the zone of a utor welded joint the combined action of bending and shear forces, similar to that which occurs during the operation of a vertical cylindrical tank. To assess the distribution of the stress-strain state in the proposed design of the sample under its loading, the finite element modeling was performed in the ANSYS software package. It showed the fundamental correspondence of the stress distribution in the zone of the utor node in the sample and in the real tank. The experimental studies consisted in carrying out tests for the durability of a series of 16 samples loaded with the maximum force in the cycle, causing the calculated stresses in the zone of the welded utor node in the range of 100–200 % from the maximum permissible ones. The obtained results showed that the maximum loaded zone, where the destruction of the samples occurred, is the near-seam zone of the utor welded joint on the inside of the tank. This corresponds to the statistics of the real tank failures. It is established that the developed methodology ensures the possibility of carrying out correct resource tests of the tank utor welded joints. It is also possible to vary the stress-strain state scheme within a wide range in the area of the utor welded joint by changing the design parameters of the test sample. In compliance with the regulated welding technologies and the absence of unacceptable defects in the welded joint, the utor node has a high resource, which significantly exceeding 50 years of the tank operation.

scholarly journals Influence of the concrete strength and the type of supports on the stress-strain state of a hyperbolic paraboloid shell footbridge structure

2021 ◽  
Vol 17 (4) ◽  
pp. 379-390
Author(s):  
David Cajamarca-Zuniga ◽  
Sebastian Luna
Keyword(s):  
Thin Shell ◽  
Strain State ◽  
Concrete Strength ◽  
Design Parameters ◽  
Live Load ◽  
Structural Behaviour ◽  
Stress Strain ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Stress Strain State

Relevance. This work is the first in a series of publications on the selection of a suitable analytical surface for implementation as a self-supporting structure for a thin shell footbridge. The study on the influence of concrete strength, live load position and support types on the stress-strain state of a hyperbolic paraboloid (hypar) shell is presented. Objective - to define the initial design parameters such as the appropriate concrete strength and the support type that generates the best structural behaviour to perform the subsequent structural design of a thin shell footbridge. Methods. The static finite element analysis was performed for 4 compressive strengths of concrete (28, 40, 80, 120 MPa) which correspond normal, high and ultra-high resistance concrete, 5 different live load arrangements and 3 different support conditions. Results. The shell model with pinned (two-hinged) supports shows the same vertical displacements as the model with fixed supports (hingeless). For the studied shell thickness, in terms of stress behaviour, the model with pinned ends is more efficient. The combination of two-hinged supports with 80 MPa concrete strength shows a better structural performance.

Using FEM Analysis for Evaluating Lifetime of the Turbine Blades Repaired by Different Kinds of Titanium and Nickel Alloys

2008 ◽  
Vol 47-50 ◽  
pp. 37-40
Author(s):  
Aleksandrs Korjakins ◽  
Sergejs Gluhihs ◽  
Andrejs Popovs ◽  
Aleksandr Tiskunov
Keyword(s):  
Strain State ◽  
Turbine Blades ◽  
Fem Analysis ◽  
Laser Forming ◽  
Stress Strain ◽  
Element Analysis ◽  
Stress Strain State ◽  
Wide Range ◽  
Direct Laser ◽  
Attractive Option

With increasing attention being devoted to the problem of reducing service costs for a wide range of turbines and compressors, an attractive option is repair of damaged blades, instead of replacing them by new ones. A lot of different methods are used to repair blades and other parts of turbines and compressors. The processes of laser metal deposition (LMD) and direct laser forming (DLF) are modern methods used to repair blades made of titanium alloys. In the present study, the finite element analysis (FEM) has been applied to determine the stress-strain state of the repaired blades in service conditions. Different forms and sizes of the damaged zones have been analyzed. Several kinds of alloys, such as Incoloy 903, Carlson C800 and Inconel 718, appropriate for the LMD and DLF methods, have been utilized in repairing the blades. Two kinds of blades, with and without cooling hollows, have been examined. Lifetime of the repaired turbine has been evaluated by comparing the results obtained from the modal and stress-strain state analyses of the repaired and original parts. The results allow evaluating influence of sizes and forms of the damaged zones, as well as choice of the alloys applied, on lifetime of the repaired blades.

scholarly journals The stress-strain state determination in pipelines welded joints

2017 ◽  
Vol 0 (16) ◽  
pp. 105-109
Author(s):  
Ольга МиколаЇвна Алексейчук ◽  
Сергій Іванович Трубачев
Keyword(s):  
Welded Joints ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State ◽  
State Determination

scholarly journals Influence of the sequence of erection of build-ings on the formation of the stress-strain state of the system «base-foundation-overhead structures»

2020 ◽  
pp. 32-44
Author(s):  
Liudmyla Skochko ◽  
Artem Shabaltun
Keyword(s):  
Strain State ◽  
Design Parameters ◽  
Soil Base ◽  
Stress Strain ◽  
High Rise ◽  
Stress Strain State ◽  
Subsequent Section ◽  
The Impact ◽  
Ground Structures ◽  
Formulation Of Problems

The influence of the order of construction of houses on the formation of the stress-strain state of the system "foundation-foundation-above-ground structures" is investigated For this purpose, several options for setting tasks for the phased construction of multi-section building sections are considered. With this in mind, it should be noted that the construction of each subsequent section has an impact on the built entirely or partially adjacent section. That is why this effect should be investigated to predict how serious this impact may be, and to draw appropriate constructive decisions. Thus, the main objectives of the study are: Creation of SEM without taking into account the stages of construction of the house; Calculation of a house with a phased loading of 5 floors. Taking into account changes in the order of construction of sections; Formation of SEM taking into account the sequence of erection of sections without including the sequence of erection of floors within the boundaries of the current section; Research of the impact of the calculation of sections of a multi-section building without and taking into account the summary of subsequent sections. The research of the impact of the sequence of construction and installation of the object will allow us to assess the stress-strain scheme at all stages of construction, so changes in the behavior of the scheme will be recorded at all stages of construction specified by the designers. To do this, the change in the stress-strain state (VAT) of the system "foundation - foundations - above-ground structures" must be modeled with different options for stages of construction, taking into account the real parameters of the soil base and so on. The interaction of piles in different zones of sections, the work of grids in the foundations of high-rise buildings are considered. The research was carried out with the help of numerical modeling of the system "foundation - foundations - aboveground constructions". The redistribution of forces in the piles depending on the formulation of problems on the stages of construction of sections and design parameters (location of piles in characteristic zones, the influence of the stiffness of the aboveground part on the redistribution of forces). Characteristic zones in the foundation are distinguished: they are central, lateral, angular and especially at the joints of adjacent sections. The redistribution of efforts between piles and a grid is revealed.  

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