Untangling the mechanics of entanglement in slide-ring gel towards both super-deformability and toughness

Soft Matter ◽  
2022 ◽  
Author(s):  
Ziyu Xing ◽  
Dong-Wei Shu ◽  
Haibao Lu ◽  
Yong Qing Fu
Keyword(s):  
Large Deformation ◽  
Dynamic Properties ◽  
Critical Role ◽  
High Strength ◽  
Polymer Systems

Entanglement plays a critical role in determining dynamic properties of polymer systems, e.g., resulting in slip links and pulley effects for achieving their large deformation and high strength. Although it...

Dynamic Attenuation and Compressive Characterization of Syntactic Foams

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Bhaskar Ale ◽  
Carl-Ernst Rousseau
Keyword(s):  
High Performance ◽  
Volume Fraction ◽  
Ultrasonic Attenuation ◽  
Dynamic Properties ◽  
High Strength ◽  
Particulate Composites ◽  
Syntactic Foams ◽  
Core Elements ◽  
Marine Applications ◽  
Damping Materials

Hollow particulate composites are lightweight, have high compressive strength, are low moisture absorbent, have high damping materials, and are used extensively in aerospace, marine applications, and in the manufacture of sandwich composites core elements. The high performance of these materials is achieved by adding high strength hollow glass particulates (microballoons) to an epoxy matrix, forming epoxy-syntactic foams. The present study focuses on the effect of volume fraction and microballoon size on the ultrasonic and dynamic properties of Epoxy Syntactic Foams. Ultrasonic attenuation coefficient from an experiment is compared with a previously developed theoretical model for low volume fractions that takes into account attenuation loss due to scattering and absorption. The guidelines of ASTM Standard E 664-93 are used to compute the apparent attenuation. Quasi-static compressive tests were also conducted to fully characterize the material. Both quasi-static and dynamic properties, as well as coefficients of attenuation and ultrasonic velocities are found to be strongly dependent upon the volume fraction and size of the microballoons.

Mechanical Behaviour of Beta Titanium Alloys

2021 ◽  
Vol 1016 ◽  
pp. 964-970
Author(s):  
Nageswara Rao ◽  
Geetha Manivasagam
Keyword(s):  
Heat Treatment ◽  
Titanium Alloys ◽  
Dynamic Properties ◽  
Solution Treatment ◽  
Weight Ratio ◽  
High Strength ◽  
Static Properties ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Beta Titanium Alloys

Beta titanium alloys have several attractive features; this has resulted in this group of alloys receiving much attention since 1980’s. Among the attributes which distinguish them for their superiority over other structural materials are (i) high strength to which they can be heat treated, resulting in high strength to weight ratio (ii) high degree of hardenability which enables heat treatment in large section sizes to high strength levels (iii) excellent hot and cold workability, making them as competitive sheet materials etc. The standard heat treatment consists of solution treatment in beta or alpha plus beta phase field followed by aging. However, certain aging treatments can render the materials in a state of little or no ductility; the designer has to be aware of this behaviour and has to keep away from such treatments while working with the materials. Such unfavourable aging treatments may adversely affect not only the static properties such as reduction in area and elongation in a tensile test, but also dynamic properties such as impact toughness. Results of fractographic studies are in line with those of mechanical testing. The authors would present the foregoing analysis, based primarily on the wide-ranging researches they carried out on beta titanium alloy Ti15-3 and to some extent data published by researchers on other grades of beta titanium alloys. An attempt is made to explain the mechanisms underlying the embrittlement reactions that take place in beta titanium alloys under non-optimal aging treatments.

scholarly journals Equivalent substitution criteria of aluminum for steel and its application in automobile structures

2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091122
Author(s):  
Song Li ◽  
Jiantao Bai ◽  
Xinchen Wang ◽  
Limin Song ◽  
Kai Luo ◽  
...  
Keyword(s):  
Large Deformation ◽  
Small Deformation ◽  
High Strength ◽  
Steel Tube ◽  
Equal Mass ◽  
Body Structure ◽  
Cross Sectional ◽  
Hollow Section ◽  
Automobile Body ◽  
Triple Cell

Lightweight automobile body structure, made of aluminum, can extend the endurance mileage of electric automobile. However, the mechanisms for the application of aluminum in automobile body structure are not clear until now. The main contribution of this work is to propose a method of equivalent substitution criteria of aluminum for steel. This method researches small deformation and large deformation under bending mode. First, formulations of cross-sectional properties, including open, single-cell, double-cell, three-cell, and four-cell sections, are derived, and equivalent substitution criteria in the case of small deformation, which include equal stiffness design and equal strength design, are initially proposed. Second, in the case of large deformation, the steel circular tube and channel tube are substituted by aluminum tube under equivalent stiffness. The bending resistance of five types of tubes, including rectangular hollow section, rectangular hollow section with double-cell, rectangular hollow section with triple-cell, mild steel, and high-strength steel tube, are, respectively, compared considering crashworthiness under equal mass. Third, the side frame and chassis frame examples verify the effectiveness of the proposed method, which is universal and can also be applied in aerospace structures.

The Role of Filler Networking in Dynamic Properties of Filled Rubber

1999 ◽  
Vol 72 (2) ◽  
pp. 430-448 ◽  
Author(s):  
Meng-Jiao Wang
Keyword(s):  
Dynamic Properties ◽  
Cyclic Strain ◽  
Considerable Change ◽  
Dynamic Strain ◽  
Additional Energy ◽  
Polymer Systems ◽  
Filled Rubber ◽  
Filler Network ◽  
The Impact

Abstract Fillers, when added to polymer systems, are known to cause a considerable change in dynamic properties. For a given polymer and cure system, this paper discusses the impact of the filler network, both its strength and architecture, on the dynamic modulus and hysteresis during dynamic strain. It was found that the filler network can substantially increase the effective volume of the filler due to rubber trapped in the agglomerates, leading to high elastic modulus. The amount of trapped rubber was estimated according to Van der Poel theory. During cyclic strain, while the stable filler network can reduce the hysteresis of the filled rubber, the breakdown and reformation of the filler network would cause an additional energy dissipation resulting in higher hysteresis.

Observation of Defects in Crystalline Polymers by HREM

MRS Bulletin ◽  
1987 ◽  
Vol 12 (8) ◽  
pp. 27-35 ◽  
Author(s):  
David C. Martin ◽  
Edwin L. Thomas
Keyword(s):  
High Resolution ◽  
Volume Fraction ◽  
Imaging Techniques ◽  
Critical Role ◽  
Crystalline Polymer ◽  
High Resolution Electron Microscopy ◽  
Inorganic Materials ◽  
Polymer Chains ◽  
Polymer Systems ◽  
Crystalline Polymers

The importance of crystalline defects in determining the macroscopic properties of metals, ceramics, and semiconductors is well known. Crystalline polymers also exhibit defect structures, but analyzing of defects in polymers is more difficult because the topological connectivity of the covalently bonded polymer chains means that solid polymers typically exhibit larger amounts and types of disorder than crystals of low molar mass molecules. Imaging is also more complex because of the inherent electron beam sensitivity of these typically organic materials. Recent developments in synthesis and processing have made it possible to achieve very highly ordered polymer systems. Defects in these materials will undoubtedly play a critical role in determining mechanical properties, optical behavior, and transport properties such as electrical conductivity.Direct imaging techniques are particularly important for studying defects because the typically low volume fraction of defects in the crystalline phase makes diffraction experiments difficult if not impossible. Also, in diffraction information about the relative orientation of individual crystallites is lost. It is not surprising, then, that High Resolution Electron Microscopy (HREM) has become extremely important for studying defects in inorganic materials systems. HREM studies of polymers have been limited by the beam sensitivity of organic compounds. Recently, however, high voltage instruments, low dose techniques, and image processing procedures have made it possible to obtain lattice images in systems with beam sensitivities as low as 0.003 C/cm2 (2 e-/A2).This review discusses the nature of defects in crystalline polymer systems and illustrates how proper application of high resolution imaging techniques promises to answer questions in polymer morphology.

Sign in / Sign up

Export Citation Format

Share Document