An Inverse Design Method of Buckling-Guided Assembly for Ribbon-Type 3D Structures

2019 ◽  
Vol 87 (3) ◽  
Author(s):  
Zheng Xu ◽  
Zhichao Fan ◽  
Yanyang Zi ◽  
Yihui Zhang ◽  
Yonggang Huang
Keyword(s):  
Cross Section ◽  
3D Structure ◽  
Experimental Studies ◽  
Functional Materials ◽  
Optimization Method ◽  
Inverse Design ◽  
Torsional Angle ◽  
3D Structures ◽  
Practical Applications ◽  
The Cross

Abstract Mechanically guided three-dimensional (3D) assembly based on the controlled buckling of pre-designed 2D thin-film precursors provides deterministic routes to complex 3D mesostructures in diverse functional materials, with access to a broad range of material types and length scales. Existing mechanics studies on this topic mainly focus on the forward problem that aims at predicting the configurations of assembled 3D structures, especially ribbon-shaped structures, given the configuration of initial 2D precursor and loading magnitude. The inverse design problem that maps the target 3D structure onto an unknown 2D precursor in the context of a prescribed loading method is essential for practical applications, but remains a challenge. This paper proposes a systematic optimization method to solve the inverse design of ribbon-type 3D geometries assembled through the buckling-guided approach. In addition to the torsional angle of the cross section, this method introduces the non-uniform width distribution of the initial ribbon structure and the loading mode as additional design variables, which can significantly enhance the optimization accuracy for reproducing the desired 3D centroid line of the target ribbon. Extension of this method allows the inverse design of entire 3D ribbon configurations with specific geometries, taking into account both the centroid line and the torsion for the cross section. Computational and experimental studies over a variety of elaborate examples, encompassing both the single-ribbon and ribbon-framework structures, demonstrate the effectiveness and applicability of the developed method.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

scholarly journals Experimental study on the thermal behaviour of fire exposed slim-floor beams

2018 ◽  
Author(s):  
Vicente Albero ◽  
Ana Espinós ◽  
Enrique Serra ◽  
Manuel L. Romero ◽  
Antonio Hospitaler
Keyword(s):  
Cross Section ◽  
Thermal Behaviour ◽  
Thermal Model ◽  
Elevated Temperatures ◽  
Experimental Studies ◽  
Composite Beams ◽  
Technical Equipment ◽  
Design Code ◽  
Special Configuration ◽  
The Cross

Steel-concrete composite beams embedded in floors (slim-floors) offer various advantages such as the floor thickness reduction or the ease of installation of under-floor technical equipment. However, this typology presents important differences in terms of thermal behaviour, as compared to other composite beams, when exposed to elevated temperatures. These differences are due to their special configuration, being totally contained within the concrete floor depth. Moreover, the current European fire design code for composite steel-concrete structures (EN 1994-1-2) does not provide any simplified thermal model to evaluate the temperature evolution of each slim-floor part during a fire. Additionally, only a few experimental studies can be found which may help understand the thermal behaviour of these composite beams. This paper presents an experimental investigation on the thermal behaviour of slim-floor beams. Electrical radiative panels were used in the test setup to produce the thermal heating. The thermal gap between the lower flange of the steel profile and the bottom steel plate was studied, being found to be one of the most influential elements over the cross-section temperature gradient. The experimental campaign was developed by varying the cross-section configuration in order to evaluate the influence of this parameter over the slim-floor thermal behavior. Finally, the experiments carried out were used to develop and calibrate a finite element thermal model which may help in further research on the thermal behaviour of slim-floor composite beams.

Flexoelectric effect induced in an anisotropic bar with cubic symmetry under torsion

2019 ◽  
Vol 25 (3) ◽  
pp. 820-837
Author(s):  
AR El Dhaba ◽  
ME Gabr
Keyword(s):  
Cross Section ◽  
Gradient Elasticity ◽  
Strain Gradient Elasticity ◽  
Cubic Symmetry ◽  
Rectangular Shape ◽  
Practical Applications ◽  
Flexoelectric Effect ◽  
The Cross ◽  
Gradient Elasticity Theory ◽  
Physical Quantities

In this article, we study the flexoelectricity induced in a prismatic anisotropic bar due to torsion. The simplified strain gradient elasticity theory is considered in this study. The bar is uniform, that is, any cross-section of the bar has a rectangular shape with cubic internal structure symmetry. The traction and higher traction forces effect on the deflection and spontaneous polarization of the bar with different boundary conditions are also discussed. The induced wedge forces are also considered during this study. The magnesium oxide (MgO) physical quantities values are chosen to present a numerical example as one of the practical applications of the problem. The results are discussed and introduced graphically. The most interesting finding in this study is the wedge force directions. When the displacements inside the cross-section of the bar are uniformly distributed, the resultant wedge forces have the same inclination with the cross-section boundary. Meanwhile, if the displacement is not uniformly distributed, the wedge force inclinations with the cross-section boundary are not equal.

Reaction cross section calculations via second beta decay using the activation method for the p-process

2019 ◽  
Vol 97 (11) ◽  
pp. 1206-1209
Author(s):  
Ezgi Tantoğlu ◽  
Nalan Özkan ◽  
R. Taygun Güray
Keyword(s):  
Beta Decay ◽  
Cross Section ◽  
Cross Sections ◽  
Half Life ◽  
Reaction Cross Section ◽  
Experimental Studies ◽  
Reaction Cross ◽  
Activation Method ◽  
Alternative Method ◽  
The Cross

There are 35 proton-rich isotopes between 74Se and 196Hg that cannot be synthesized through neutron captures and β− decays (s- and r-processes). A third process is therefore required for the production of these nuclei, the so-called p-process. The abundance and the origin of the p-nuclei are still not fully understood even though significant experimental and theoretical efforts in astrophysical modeling have been expended in the last two decades. The experimental studies with the activation method to measure cross sections of the relevant reactions have some limitations: the reaction product must be radioactive, should have an appropriate half-life, and its decay should be followed by proper γ-radiations. If the cross section cannot be calculated with the radiation followed by the first beta decay of the product, it can be measured using the second beta decay as an alternative method. In this study, the method and candidate reactions for the cross-section measurements via the second beta decay of the reaction product using the activation method are discussed.

scholarly journals COLD ROLLING OF PRE-PROFILED STRIP FROM ALUMINUM ALLOY EN AW-1050

2020 ◽  
pp. 93-101
Author(s):  
Serhii Bondarenko ◽  
Olexandr Grydin ◽  
Yaroslav Frolov ◽  
Olga Kuzmina ◽  
Oleksandr Bobukh
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Cold Rolling ◽  
Cross Section ◽  
Steel Strip ◽  
Experimental Studies ◽  
Cold Plastic Deformation ◽  
Aluminum Strip ◽  
The Cross

Specialists of metallurgy and mechanical engineering are intensively working at materials with controlled properties. In fact, at this stage we are already talking about the design of new materials for the specific tasks of the industry. One of the ways to achieve the regulated mechanical properties of metal products is to use the influence of plastic deformation with its different parameters in individual sections of the deformable material. In this study, we studied the effect of cold rolling on the properties of a strip of aluminum alloy EN AW-1050 with artificially created differences in the deformation parameters in different parts of the cross section of the profile. For this, a pre-shaped sample was prepared by conducting joint cold rolling of a strip of the specified material 420 mm long, 180 mm wide and 2.9 mm thick with a steel profiling tape 80 mm wide and 2 mm thick superimposed on it (length of an aluminum strip and steel profiling tape are the same). As a result of joint deformation, the steel strip rolled into the base metal and changed the geometry of the cross section and the properties of the obtained strip. Next, the obtained strip was subjected to heat treatment and rolled in a duo mill. After rolling, thin samples were made from fabricated flat strips to assess mechanical properties, in particular tensile tests were performed according to ISO 6892-1: 2009 and Brinell hardness tests were performed according to ISO 6506-1: 2014. Experimental studies of cold rolling of strips with profiled cross section of aluminum alloy EN AW-1050 were carried out. The possibility of forming heterogeneous properties in a flat aluminum strip by cold plastic deformation is shown and the maximum average values of the increase in the main indicators of mechanical properties on individual elements of the strip are determined. The maximum difference between the mechanical properties of the thick and thin elements of the profiled strip is observed in the hardness index and reaches 37.5%. The maximum obtained average value of the increase in yield strength and tensile strength is 26% and 18%, which is achieved with true deformation of the thick element of the profiled strip 0.165 and 0.234.

scholarly journals Experimental Studies of Reduction Effects on Seismic Stresses in the Cross Section of Shield Tunnels.

1994 ◽  
pp. 107-116
Author(s):  
Mikio Takeuchi ◽  
Yoshiaki Idota ◽  
Tadashi Takahashi ◽  
Takashi Misawa
Keyword(s):  
Cross Section ◽  
Experimental Studies ◽  
The Cross

scholarly journals REINFORCEMENT UNDER LOAD OF DEFORMED COMPRESSED STEEL RAIL TRUSS

2021 ◽  
Vol 11 (3) ◽  
pp. 26-31
Author(s):  
Igor K. RODIONOV ◽  
Evgeniy G. SAFRONOV
Keyword(s):  
Cross Section ◽  
Experimental Studies ◽  
Steel Rail ◽  
Industrial Buildings ◽  
The Cross ◽  
Technical Solutions ◽  
Steel Trusses

The results of the survey of steel trusses covering six industrial buildings are presented. In particular, the presence of various forms of defects of compressed rods was revealed: general bends in the plane and out of the plane of the truss, local perishes of the shelves - grinding and grinding. The necessity of strengthening the rods for further operation of the structures is determined. The proposed technical solutions for strengthening deformed rods are presented. When developing technical solutions, we tried to achieve, if possible, compensation for the damaged part of the cross-section (for locally damaged rods) and bringing the axis of the repaired rod to the design position (for rods with common bends). To confi rm the eff ectiveness of the proposed solutions, experimental studies were conducted. A brief analysis of the results is given.

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