Capillary forces drive buckling, plastic deformation, and break-up of 3D printed beams

Soft Matter ◽  
2021 ◽  
Vol 17 (14) ◽  
pp. 3886-3894
Author(s):  
Christopher S. O’Bryan ◽  
Alexandria Brady-Miné ◽  
Crystal J. Tessmann ◽  
Amanda M. Spotz ◽  
Thomas E. Angelini
Keyword(s):  
Plastic Deformation ◽  
Soft Materials ◽  
Capillary Forces ◽  
Plastic Deformations ◽  
Elastic And Plastic Deformations ◽  
3D Printed ◽  
Break Up

Capillary forces acting at the interfaces of soft materials lead to elastic and plastic deformations and instabilities that result in buckling, coiling, and break-up of 3D printed beams.

Numerical Analysis for Influence of Plastic and Elastic Deformation of Rough Surfaces on PEHL for Line Contacts

Tribology ◽  
2005 ◽  
Author(s):  
R. J. Niu ◽  
P. Huang
Keyword(s):  
Plastic Deformation ◽  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Paper Analysis ◽  
Line Contact ◽  
Plastic Deformations ◽  
Rolling Contacts ◽  
Line Contacts ◽  
Elastic And Plastic Deformations ◽  
Strain Relationship

In the present paper, analysis of elasto-plasto-hydrodynamic lubrication (PEHL) in the line contact is carried out to investigate the effect of heavily loaded roll-over on the change in profile of indents. The pressure and film thickness profiles are obtained to solve the Reynolds and film thickness equations simultaneously. And, both the elastic and plastic deformations of the contact, featured with an indent, have been considered. A multi-grid numerical algorithm used in EHL of line contacts is modified and then used for the oil lubricated rolling contacts. In the program, stress and plastic deformation of the indent profile are calculated with the hardening plastic stress-strain relationship according to the theories of plasticity when pressure excesses the yield stress. The results, with and without considering plastic deformation, are compared to show the different influences on the pressure and film thickness. Analysis shows that since the plastic deformation will change the surface roughness, it will significantly change the pressure but film thickness.

Effect of elastic and plastic deformations on tribological behavior of graphene-reinforced Ni3Al matrix composites

2017 ◽  
Vol 232 (10) ◽  
pp. 1261-1272 ◽  
Author(s):  
Yuchun Huang ◽  
Xiaoliang Shi ◽  
Kang Yang ◽  
Jialiang Zou ◽  
Qiao Shen ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Tribological Properties ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Plastic Deformations ◽  
Wear Resistant ◽  
Elastic And Plastic Deformations ◽  
Resistant Layer ◽  
Al Matrix ◽  
Self Lubricating Composites

The elastic and plastic deformations have significant effect on the tribological properties of the graphene-reinforced Ni3Al matrix self-lubricating composites. The primary purpose of this study is to investigate the tribological behavior and wear mechanisms of graphene-reinforced Ni3Al matrix self-lubricating composites by researching the effects of different loads and the corresponding friction heat on the elastic or plastic deformation. The dry sliding tribology tests of graphene-reinforced Ni3Al matrix self-lubricating composites are carried out at the loads of 7, 10, 13, and 16N, respectively. The elastic or plastic deformation is judged by comparing the yield stress with the contact stress analyzed by the numerical simulation method. It is found that graphene-reinforced Ni3Al matrix self-lubricating composites exhibit good tribological properties at 13 N due to the elastic deformation, leading to the formation of relatively stable wear resistant layer. Graphene-reinforced Ni3Al matrix self-lubricating composites show poor tribological performance at 16 N for the plastic deformation, resulting in the destruction of the wear resistant layer and the generation of surface cracks and material spalling. From the mechanical mechanism of wear, the plastic deformation and thermal stress are the important factors to lead to the material spalling. The results could be used to guide the selection of suitable working conditions for having good tribological performance of low wear and long service life.

scholarly journals Análise de um pavimento reforçado com geossintético a partir de resultados de ensaio em equipamento de grandes dimensões

TRANSPORTES ◽  
2011 ◽  
Vol 19 (3) ◽  
pp. 28
Author(s):  
Francis Massashi Kakuda ◽  
Alexandre Benetti Parreira ◽  
Glauco Tulio Pessa Fabbri
Keyword(s):  
Plastic Deformation ◽  
Numerical Modeling ◽  
Laboratory Tests ◽  
Resilient Modulus ◽  
Base Layer ◽  
Plastic Deformations ◽  
Elastic And Plastic Deformations ◽  
Back Calculation ◽  
Pavement Reinforcement ◽  
Elastic And Plastic Deformation

<p><strong>Resumo</strong>: O artigo analisa o beneficio do uso de uma geogrelha como reforço da camada de base de um pavimento. Seções do pavimento e subleito com dimensões próximas às reais submetidas a carregamentos cíclicos foram ensaiadas numa caixa metálica quadrada com lado de 1,5 m e altura de 1,2 m. Concluiu-se que a utilização da geogrelha proporciona a redução de deformações elásticas e permanentes, e que a eficiência do reforço posicionado na interface com o subleito é maior que a do reforço posicionado no horizonte médio da base. Foram ainda determinados os módulos de resiliência da base e do subleito a partir da retroanálise das bacias de deflexões obtidas nos ensaios. Finalmente, a análise numérica de um pavimento hipotético mostrou que a geogrelha pode proporcionar uma extensão expressiva na vida de fadiga do revestimento asfáltico.</p><p><strong>Palavras-chave</strong>: pavimentos reforçados com geosintéticos, geogrelha, ensaios de laboratório em verdadeira grandeza, deformações elásticas e plásticas sob carregamento cíclicos.</p><p><strong>Abstract</strong>: The article analyzes the benefits of the application of a geogrid as base layer pavement reinforcement. Cyclic loaded fullscale sections of pavement and subgrade were tested in a square metallic box with 1.5 m width and 1.2 m height. It was concluded that the geogrid reduces the elastic and plastic deformations and also that positioning the reinforcing at subgrade interface is more efficient than at base medium horizon. The base and subgrade resilient modulus were obtained by back calculation using the deflection basin results from the tests. Finally, a numerical modeling of a hypothetic pavement showed that the geogrid may conduct to an expressive increase of the bituminous surface life.</p><p><strong>Keywords</strong>: geosynthetic reforced pavement, geogrid, full-scale laboratory tests, elastic and plastic deformation under cyclic loadings.</p>

Microtwins of Transformation and their Effect on Excess Dislocation Density of FCC Deformed Material

2014 ◽  
Vol 1013 ◽  
pp. 72-76 ◽  
Author(s):  
Svetlana Kiseleva ◽  
Natal'ya Popova ◽  
Nina Koneva ◽  
Eduard Kozlov
Keyword(s):  
Plastic Deformation ◽  
Dislocation Density ◽  
Austenitic Steel ◽  
Internal Stresses ◽  
Plastic Deformations ◽  
Density Of Dislocations ◽  
Elastic And Plastic Deformations ◽  
Excess Density

The excess density of dislocations and internal stresses in local places of all polycrystal grain are determined. In work the methods of bending extinction contours observed by TEM is used to determine internal stresses of the deformed material. Thus depending on the deformation nature in each case components of elastic and plastic deformations or only plastic deformation was considered. The paper discusses the results of distribution of excess dislocation density and internal stresses within the grains of the austenitic steel deformed by tension (ε = 25%).

A Biomimetic Approach to the Design of the Composite Bottle Cap and Deformation Analyses

2009 ◽  
Vol 2 ◽  
pp. 59-72
Author(s):  
Li Zhi Gu ◽  
Z. Zhang
Keyword(s):  
Plastic Deformation ◽  
Structural Feature ◽  
Thin Wall ◽  
Functional Requirements ◽  
Plastic Deformations ◽  
Pressing Force ◽  
Maximum Value ◽  
Elastic And Plastic Deformations ◽  
Biomimetic Approach

On the combination analog of the mussel ripple and leaf embrace, designed a new composite bottle cap consisting of the outer body, the inner lining washer, and the resin embrace, for multi-function, especially for better seal and ready open. According to the structural feature and the functional requirements of the cap, two fundamental components, the lining washer and the outer body, were abstracted into a plate and a cylinder with thin wall, respectively. Under the pressing force the elastic and plastic deformations of both were studied with Tresca’s yielding rule and the limitation of the plastic deformation was presented when the two components were assembled into a unit. For the production of this kind of bottle cap, the maximum value of the allowance press and the maximum pressing velocity were also provided.

Buckling of Columns in the Presence of Creep

1956 ◽  
Vol 7 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Sharad A. Patel
Keyword(s):  
Critical Time ◽  
Secondary Creep ◽  
Plastic Deformations ◽  
Creep Buckling ◽  
Elastic And Plastic Deformations

SummaryThis paper is concerned with the solution of the creep buckling of columns. Instantaneous elastic and plastic deformations, as well as the transient and secondary creep, are considered. Formulae for the critical time at which a column fails are presented for integral values of the exponents appearing in the creep law.

Experimental Verification of Constitutive Equations for Creep and Plasticity Based on Overlay Models

1983 ◽  
Vol 105 (3) ◽  
pp. 277-284 ◽  
Author(s):  
P. Meijers ◽  
F. Roode
Keyword(s):  
Plastic Deformation ◽  
Room Temperature ◽  
304 Stainless Steel ◽  
Model Parameters ◽  
General Description ◽  
Time Effects ◽  
Plastic Deformations ◽  
Biaxial Load ◽  
Theoretical Predictions ◽  
Good Agreement

A general description of creep and plastic deformation based on overlay models is presented. This includes the description of time effects during plastic deformation at room temperature. A detailed procedure to obtain the model parameters is also discussed. The description has been evaluated for a large number of uniaxial and biaxial load histories on thin walled tubes. The materials involved are a 2 1/4 Cr-1 Mo steel stabilized with Niobium (WN 1.6770) and a 304 stainless steel (WN 1.4948). The theoretical predictions of the plastic deformations are found to be sufficiently accurate. The evaluation of the phenomenological description for creep shows a fairly good agreement with the real creep deformation process. Special attention requires the description of softening due to microstructural changes.

scholarly journals Orientation Dependent Mechanical Responses and Plastic Deformation Mechanisms of ZnSe Nano Films under Nanoindentation

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3014
Author(s):  
Chao Xu ◽  
Futi Liu ◽  
Chunmei Liu ◽  
Pei Wang ◽  
Huaping Liu
Keyword(s):  
Plastic Deformation ◽  
Elastic Recovery ◽  
Structural Evolution ◽  
Atomic Displacement ◽  
Deformation Mechanisms ◽  
Formation Mechanisms ◽  
Plastic Deformations ◽  
Mechanical Responses ◽  
Displacement Vectors ◽  
Dynamics Simulations

Although ZnSe has been widely studied due to its attractive electronic and optoelectronic properties, limited data on its plastic deformations are available. Through molecular dynamics simulations, we have investigated the indentations on the (001), (110), and (111) planes of ZnSe nano films. Our results indicate that the elastic modulus, incipient plasticity, elastic recovery ratio, and the structural evolutions during the indenting process of ZnSe nano films show obvious anisotropy. To analyze the correlation of structural evolution and mechanical responses, the atomic displacement vectors, atomic arrangements, and the dislocations of the indented samples are analyzed. Our simulations revealed that the plastic deformations of the indented ZnSe nano films are dominated by the nucleation and propagation of 1/2<110> type dislocations, and the symmetrically distributed prismatic loops emitted during the indenting process are closely related with the mechanical properties. By studying the evolutions of microstructures, the formation process of the dislocations, as well as the formation mechanisms of the emitted prismatic loops under the indented crystalline planes are discussed. The results presented in this work not only provide an answer for the questions about indentation responses of ZnSe nano films, but also offer insight into its plastic deformation mechanisms.

scholarly journals Estimation of the Influence of Compressed Hydrogen on the Mechanical Properties of Pipeline Steels

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6085
Author(s):  
Victor I. Bolobov ◽  
Il’nur U. Latipov ◽  
Gregory G. Popov ◽  
George V. Buslaev ◽  
Yana V. Martynenko
Keyword(s):  
Mechanical Properties ◽  
Stress State ◽  
Pressure Range ◽  
Operating Pressure ◽  
Gas Pipelines ◽  
Plastic Deformations ◽  
Hydrogen Saturation ◽  
Elastic And Plastic Deformations ◽  
Potential Losses ◽  
Pipeline Wall

Consideration of the possibility of transporting compressed hydrogen through existing gas pipelines leads to the need to study the regularities of the effect of hydrogen on the mechanical properties of steels in relation to the conditions of their operation in pipelines (operating pressure range, stress state of the pipe metal, etc.). This article provides an overview of the types of influence of hydrogen on the mechanical properties of steels, including those used for the manufacture of pipelines. The effect of elastic and plastic deformations on the intensity of hydrogen saturation of steels and changes in their strength and plastic deformations is analyzed. An assessment of the potential losses of transported hydrogen through the pipeline wall as a result of diffusion has been made. The main issues that need to be solved for the development of a scientifically grounded conclusion on the possibility of using existing gas pipelines for the transportation of compressed hydrogen are outlined.

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