scholarly journals Influence of Different Strain Hardening Models on the Behavior of Materials in the Elastic–Plastic Regime under Cyclic Loading

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5323
Author(s):  
Peter Sivák ◽  
Peter Frankovský ◽  
Ingrid Delyová ◽  
Jozef Bocko ◽  
Ján Kostka ◽  
...  

In exact analyses of bodies in the elastic–plastic regime, the behavior of the material above critical stress values plays a key role. In addition, under cyclic stress, important phenomena to be taken into account are the various types of hardening and the design of the material or structure. In this process, it is important to define several groups of characteristics. These include, for instance, the initial area of plasticity or load which defines the interface between elastic and plastic deformation area. The characteristics also include the relevant law of plastic deformation which specifies the velocity direction of plastic deformation during plastic deformation. In the hardening condition, it is also important to determine the position, size and shape of the subsequent loading area. The elasto-plastic theory was used for the analysis of special compliant mechanisms that are applied for positioning of extremely precise members of the Compact Linear Collider (CLIC), e.g., cryomagnets, laser equipment, etc. Different types of deformation hardening were used to simulate the behavior of particular structural elements in the elastic–plastic regime. Obtained values of stresses and deformations may be used in further practical applications or as default values in other strain hardening model simulations.

Author(s):  
J. W. Craggs

SynopsisA study is made of the propagation of elastic and plastic deformation in a thin plate, initially unstressed, and of infinite extent, when it is penetrated normally by a cone moving with uniform velocity. The work is an extension of unpublished researches by Sir G. I. Taylor on the corresponding problem for a thin wire, and a summary of his results is included.


Author(s):  
A.И. Притыкин

Для оценки несущей способности балок судовых конструкций надо определять их предельную нагрузку. Существующие расчетные зависимости, приводимые в справочных изданиях, далеко не всегда дают верные рекомендации, когда речь идет о балках с присоединенным пояском обшивки, который может намного превосходить размер свободного пояска. В работе проведен сравнительный анализ оценки предельной нагрузки, определяемой аналитически и путем упругопластического расчета методом конечных элементов с варьированием ширины присоединенного пояска. Рассматривался вариант упругопластического нагружения с линейным упрочнением. Полученные результаты показали, что приводимая в справочнике по СМК, зависимость для оценки предельной нагрузки балок с асимметричным профилем не совсем корректна из-за неполного включения присоединенного пояска в работу. Это дает завышенные значения предельной нагрузки. Проверены были также рекомендации по оценке прогибов балок в предельном состоянии, показавшие, что рекомендации справочника по СМК приводят к заниженным значениям прогибов. Для балок симметричного профиля расчетные зависимости справочника дают вполне удовлетворительные результаты. Отмечено, что если поперечная нагрузка вызывает текучесть стенки балки от сдвига, то влияние ширины присоединенного пояска практически не сказывается на ее несущей способности. Проанализировано также влияние величины секущего модуля на предельную нагрузку балки. For estimation of load capacity of the ship beams it is necessary to determine their limit load. Existing analytical relations, indicated in different manuals, not always give true recommendations when talk is about beams with associated plate many times exceeding dimensions of free flange. In this paper fulfilled comparative analysis of limit load, determined with analytical and elastic-plastic calculation by the finite element method. It was considered case of elastic-plastic deformation with lineal strain-hardening. Obtained results show that indicated in manual on the ship structural mechanics, relation for estimation of limit load of non-symmetric I-beams is not quite correct because of not complete inclusion of associated plate to the beam deformation. This lead to overestimation of limit loads. It was also shown that recommendations on evaluation of the deflections of beams in elastic-plastic deformations according to mentioned manual lead to much lower values of deflections. For beam with symmetric profile the relations of manual give quite satisfactory results. It was noticed, that if transverse load produces the yielding of web due to shear the influence of width of associated plate has no influence on the load capacity of beam. It was also analyzed influence of value of the strain-hardening modulus on limit load of beam.


1981 ◽  
Vol 48 (1) ◽  
pp. 35-40 ◽  
Author(s):  
V. A. Lubarda ◽  
E. H. Lee

The plastic part of an elastic-plastic deformation is that remaining when the stress, and hence the elastic strain, is reduced to zero. Elastic deformation is that produced in this purely plastically deformed material by the action of stresses up to yield. The associated exact finite-deformation kinematics shows the almost universal assumption that the total rate of deformation is the sum of elastic and plastic rates to be in error. An incremental elastic-plastic theory is developed using the nonlinear kinematics. The theory is contrasted with that in common use and anomalies in the latter are discussed.


2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.


2021 ◽  
Vol 158 ◽  
pp. 103876
Author(s):  
Qi-lin Xiong ◽  
Zhenhuan Li ◽  
Takahiro Shimada ◽  
Takayuki Kitamura

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