Visualization of Multiaxial Stress/Strain State and Evaluation of Failure Life by Developed Analyzing Program under Non-Proportional Loading

2014 ◽  
Vol 891-892 ◽  
pp. 1391-1396
Author(s):  
Shu Li Liu ◽  
Takamoto Itoh ◽  
Noriyuki Fujii
Keyword(s):  
Principal Stress ◽  
Strain State ◽  
Strain Range ◽  
Mean Stress ◽  
Damage Evaluation ◽  
Multiaxial Loading ◽  
Proportional Loading ◽  
Stress Strain ◽  
3D Loading ◽  
Failure Life

This study presents definitions of principal stress/strain range and mean stress/strain introduced by utilizing Itoh-Sakane criterion for multiaxial loading including non-proportional loading, and shows the method of calculating the non-proportional factor which expresses the severity of non-proportional loading under the multiaxial 3D loading. This paper also shows a method of visually presenting the stress/strain, the non-proportionality of loading and the damage evaluation.

scholarly journals On Stress-Strain Relations Suitable for Cyclic and Other Loading

1981 ◽  
Vol 48 (3) ◽  
pp. 479-485 ◽  
Author(s):  
D. C. Drucker ◽  
L. Palgen
Keyword(s):  
Kinematic Hardening ◽  
Cyclic Hardening ◽  
Pressure Vessels ◽  
Mean Stress ◽  
Proportional Loading ◽  
Stress Strain ◽  
Analysis And Design ◽  
First Approximation ◽  
Cyclic Straining ◽  
Independent Domain

The analysis and design of pressure vessels and other structures subjected to cyclic loading and occasional large overloads requires stress-strain relations sufficiently simple to be usable with computer programs and yet adequate to describe the essential aspects of the response of the material. One such form with two quite different options is proposed for the time-independent domain which avoids the difficulties of earlier approaches. It has the kinematic hardening attributes needed for reversal of loading, allows for cyclic hardening or softening, gives zero mean stress as the asymptotic response to cyclic straining between fixed limits of strain, and reduces to a J2 stress-hardening form for radial or proportional loading so that it can model both cyclic and other loading to a good first approximation.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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