scholarly journals Numeric simulations of surface pressure and microslip phenomena occurring in riveted joints of semi-monococque structures in effect of the action of tension field

2017 ◽  
Vol 3 (1(6)) ◽  
pp. 7
Author(s):  
Jarosław Mańkowski
Keyword(s):  
Thin Plate ◽  
Surface Pressure ◽  
Test Sample ◽  
Thin Walled Structures ◽  
Material Deformation ◽  
Riveted Joints ◽  
Thin Walled

Tension fields are shown to have an influence on surface pressure and on material deformation in the riveted joints in thin walled structures and particularly in semistressed skin structures. Stresses and materials displacements were analyzed in the riveted joints performing under such conditions. Special attention has been attached to estimation of the microslips occurring between rivets and holes. A thin plate panel has been used for the test sample, which under effort condition revealed tension fields.

scholarly journals Comparative calculation of optimal parameters of channel bent and bent closed profiles

2019 ◽  
Vol 15 (6) ◽  
pp. 415-432
Author(s):  
Alexander S. Marutyan
Keyword(s):  
Technical Solution ◽  
Optimal Parameters ◽  
Design And Optimization ◽  
Comparative Calculation ◽  
Thin Walled Structures ◽  
Riveted Joints ◽  
Composite Section ◽  
Thin Walled ◽  
Design Calculations ◽  
Technical And Economic Indicators

Relevance. A new technical solution for channel bent closed profiles (BCP), distinguished by a composite section and related to light steel thin-walled structures (LSTWS), which are distinguished by high technical and economic indicators and massive demand in industrial and civil construction, is presented. The main results of the comparative calculation of the optimal parameters of bent channels and channel horizontal bending sections are also given. Aim of the research. The purpose of the study is to show that the characteristics of LSTWS can be further improved by shaping modification profiles, combining in its composite section straight and round outlines of closed and open loops. Methods. Through experimental design and optimization and design calculations of channel profiles, their new technical solution has been developed, the originality of which is confirmed by patent examination. Results. Channel BCP consists of two tubular shelves and one wall of double thickness. For its manufacture without welded, bolted or riveted joints, the outer and inner blanks are made along the entire length with serrated longitudinal edges, the teeth of which are staggered relative to each other and mutually bent in grooves after closing a bent profile along its shelves. The bends of the gear mounts increase the collapse thickness, provide an increase in local stability and shear strength of the thin-walled elements, and also allow not to reduce the design sections. A comparative calculation of the optimal parameters of bent channels and channel bending sections for bending showed that in the first of them the strength is maximum when the ratio of the width and height of the cross section is 1/6, and in the second - 1/5.68.

scholarly journals I-shaped bent closed profiles with tubular shelves and calculation of the optimal layout of their composite sections

2020 ◽  
Vol 16 (5) ◽  
pp. 334-350
Author(s):  
Alexander S. Marutyan
Keyword(s):  
Technical Solution ◽  
Optimal Layout ◽  
Design And Optimization ◽  
Thin Walled Structures ◽  
Riveted Joints ◽  
Composite Section ◽  
Outer Pair ◽  
Thin Walled ◽  
Design Calculations ◽  
Technical And Economic Indicators

I-shaped bent closed profiles with tubular shelves are distinguished by a composite section and related to light steel thin-walled structures (LSTWS), which are characterized by high technical and economic indicators and mass demand in industrial and civil construction, which determines the relevance of the development of their new technical solutions. The aim of the work - to show that the characteristics of LSTWS can be further improved by forming profiles, combining straight and round outlines of closed and open circuits in a composite section. Methods. New technical solution, the originality of which is confirmed by patent examination, has been developed through experimental design and optimization and design calculations of I-shaped profiles. The calculation of the optimal bending layout of the composite sections of I-shaped profiles of horizontal billets from sheet blanks, identical and unequal in thickness, including bisteel modifications, is made. Results. The I-shaped bent closed profiles consists of two tubular shelves and one wall of double thickness. For its manufacture without welded, bolted or riveted joints, the outer pair and inner pair blanks are made along the entire length with serrated longitudinal edges, the teeth of which are staggered relative to each other and mutually bent in grooves after closing a bent profile along its shelves. The bends of the gear mounts increase the collapse thickness, provide an increase in the local stability and shear strength of the thin-walled elements, and also allow not to reduce the design sections. The calculation of the optimal layout of I-shaped profiles horizontal bend for bending showed that its strength is maximum when the ratio of the width and height of 1/5.2 and equal thicknesses of shelves and walls.

scholarly journals Curved closed profiles and calculation of their optimal parameters

2019 ◽  
Vol 15 (1) ◽  
pp. 33-43
Author(s):  
Alexander S Marutyan
Keyword(s):  
Shear Strength ◽  
Technical Solution ◽  
Developmental Studies ◽  
Optimal Parameters ◽  
Thin Walled Structures ◽  
Riveted Joints ◽  
Thin Walled ◽  
Design Calculations ◽  
Technical And Economic Indicators ◽  
Patent Examination

Relevance. A new technical solution of bent-closed profiles relating to light steel thin-walled structures (LSTS), which have high technical and economic indicators and are widely used in industrial and civil construction, is presented. Aim of the research. The characteristics of thin-walled structures can be further enhanced by shaping the modification of profiles, combining in its composition the outlines of closed and open outlines. Methods. By means of developmental studies and optimization and design calculations for bent-closed profiles, their new technical solution was developed, the originality of which was confirmed by patent examination. Results. New curved closed profiles (CCP) consist of a tubular part of a single thickness and a double-thickness rib. For their manufacture without welded, bolted or riveted joints, the sheet blank is made along the entire length with serrated longitudinal edges, the teeth of which are arranged relative to each other in a staggered manner and mutually bent in grooves between themselves after the curved profile is closed along its edge. The bends of the gear fasteners increase the thickness of the collapse and provide an increase in the shear strength of the joints of thin-walled elements. With equal dimensions in height and width of the CCP, they are optimized by the criterion of uniform stability, which is the same from the plane and in the plane of the supporting structure. Additionally, a series of pentagonal, triangular and trapezoidal profiles are presen- ted, in which the lateral faces are inclined relative to the vertical at angles of 45 and 60 degrees.

scholarly journals Modelling Method of Dynamic Characteristics of Marine Thin-Walled Structure

2019 ◽  
Vol 26 (4) ◽  
pp. 39-46
Author(s):  
Do Van Doan ◽  
Adam Szeleziński ◽  
Lech Murawski ◽  
Adam Muc
Keyword(s):  
Numerical Model ◽  
Rectangular Plate ◽  
Thin Plate ◽  
Vibration Analysis ◽  
Three Dimensional ◽  
Rectangular Thin Plate ◽  
Thin Rectangular Plate ◽  
Thin Walled Structures ◽  
Modelling Method ◽  
Thin Walled

AbstractThin-walled structures are very popular in industries, especially in the field of shipbuilding. There are many types of equipment and structures of ships, which are made up of thin-walled structures such as hull, deck and superstructure. Therefore, the analysis and understanding of the static and dynamic characteristics of a thin-walled structure are very important. In this article, we focus on vibration analysis of a typical thin-walled structure-rectangular plate, a basic structure of the hull. Vibration analysis of a rectangular thin plate is conducted by two methods: numerical modelling method of the finite element on Patran-Nastran software platform and experimental method implemented in the laboratory of Gdynia Maritime University. Thin rectangular plate is fixed one end by four clamping plates and is modelled with finite elements and different meshing densities. The numerical model of thin rectangular plate is divided into four cases. Case 1, thin rectangular plate, and clamping plates are modelled with two-dimensional elements. Case 2, the rectangular thin plate is modelled with two-dimensional elements; the clamping plates are modelled with three-dimensional elements. Case 3, both the rectangular thin plate and clamping plates are modelled with three-dimensional elements. Case 4, the rectangular thin plate, and clamping plates are modelled with three-dimensional elements with larger mesh density to increase the accuracy of the calculation results. After that, the results of vibration analysis according to the numerical modelling method on Patran-Nastran software platform for these cases were compared with the measurement results. From there, assess the accuracy of analysis results of selected numerical model methods and the ability to widely apply this numerical model method to other marine structures.

Frame-Monolithic Technology of Construction of Low-Rise Buildings Made of Foam Gypsum and Steel Thin-Walled Structures

2018 ◽  
Vol 762 (8) ◽  
pp. 36-39 ◽  
Author(s):  
B.G. BULATOV ◽  
◽  
R.I. SHIGAPOV ◽  
M.A. IVLEV ◽  
I.V. NEDOSEKO ◽  
...  
Keyword(s):  
Thin Walled Structures ◽  
Thin Walled

scholarly journals Fracture Mechanical Analysis of Thin-Walled Cylindrical Shells with Cracks

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 592
Author(s):  
Feng Yue ◽  
Ziyan Wu
Keyword(s):  
Fracture Mechanics ◽  
Tensile Stress ◽  
Failure Modes ◽  
Cylindrical Shells ◽  
Crack Tip ◽  
Mechanical Analysis ◽  
J Integral ◽  
Thin Walled Structures ◽  
Circumferential Tensile Stress ◽  
Thin Walled

The fracture mechanical behaviour of thin-walled structures with cracks is highly significant for structural strength design, safety and reliability analysis, and defect evaluation. In this study, the effects of various factors on the fracture parameters, crack initiation angles and plastic zones of thin-walled cylindrical shells with cracks are investigated. First, based on the J-integral and displacement extrapolation methods, the stress intensity factors of thin-walled cylindrical shells with circumferential cracks and compound cracks are studied using linear elastic fracture mechanics, respectively. Second, based on the theory of maximum circumferential tensile stress of compound cracks, the number of singular elements at a crack tip is varied to determine the node of the element corresponding to the maximum circumferential tensile stress, and the initiation angle for a compound crack is predicted. Third, based on the J-integral theory, the size of the plastic zone and J-integral of a thin-walled cylindrical shell with a circumferential crack are analysed, using elastic-plastic fracture mechanics. The results show that the stress in front of a crack tip does not increase after reaching the yield strength and enters the stage of plastic development, and the predicted initiation angle of an oblique crack mainly depends on its original inclination angle. The conclusions have theoretical and engineering significance for the selection of the fracture criteria and determination of the failure modes of thin-walled structures with cracks.

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