Biomimetic Application Potential of Agave sisalana Mechanical Properties, Lightness, Resistance Strategies, and Life Cycle for Digital Fabrication

Author(s):  
Rodrigo Araújo ◽  
Amilton Arruda ◽  
Jorge Lino Alves ◽  
Theska Soares ◽  
Tarciana Andrade ◽  
...  
2019 ◽  
Vol 90 (5-6) ◽  
pp. 710-727 ◽  
Author(s):  
Yiwei Ouyang ◽  
Xianyan Wu

In order to review the most effective ways to improve the mechanical properties of composite T-beams and further increase their application potential, research progress on the mechanical properties of textile structural composite T-beams was summarized based on two-dimensional (2-D) ply structure composite T-beams, delamination resistance enhanced 2-D ply structure T-beams, and three-dimensional (3-D) textile structural composite T-beams; future research directions for composite T-beams were also considered. From existing literature, the research status and application bottlenecks of 2-D ply structure composite T-beams and T-beams with enhanced delamination resistance performance were described, as were the specific classification, research progress, and mechanical properties of 3-D textile structural composite T-beams. In addition, the superior mechanical properties of 3-D braided textile structural composite T-beams, specifically their application potential based on excellent delamination resistance capacity, were highlighted. Future research directions for composite T-beams, that is, the applications of high-performance raw materials, locally enhanced design, structural blending enhancement, functionality, and intelligence are presented in this review.


2018 ◽  
Vol 936 ◽  
pp. 116-120
Author(s):  
Rahmat Nurcahyo ◽  
Djoko Sihono Gabriel ◽  
Wakhid L. Ikhsan

Impurity and contaminated waste of flexible plastic packaging will not be viable as raw materials for secondary recycling. This problem could be avoided by repetitive implementation of material value conservation through material purity protection since the product design activities up to the end of packaging life cycle. This paradigm also creates new sequential life cycles of products rather than once when only virgin materials were used as raw materials. With repetitive implementation of material value conservation and serial testing in a polymer laboratory, a type of virgin plastic pellet recycled up to the 8th stage of secondary recycling, and then the mechanical properties of materials tested according to the American Society for Testing and Materials (ASTM) standards. This research revealed that flexible plastic packaging materials that managed by Material Value Conservation (MVC) implementations were suitable for secondary recycling in producing the viable quality of recycled plastic pellets in mechanical properties measures, and leverage the potential of virgin plastic pellets utilization. Because of MVC implementations protected the purity of materials intensively, and then increased the value of recycled plastic pellets as raw materials for the new life cycle of plastic products.


Author(s):  
Murat Bakirov ◽  
Sergei Chubarov ◽  
Igor Frolov ◽  
Joerg Gastrock

Ever-increasing requirements for reliability and safety of equipment in nuclear power plants (NPP) dictate a necessity to obtain reliable and validated information about the condition of materials in the most safety-relevant and economically vital systems structures and components (SSC). Thus it is a state of science and technology approach to use one method, one methodic and one methodology to facilitate these goals with the purpose of keeping NPPs operating safely by virtue of knowing the state of ageing they are in (with respect to design limits and margins). Method of the control/measurement/testing - how to conduct measurements; methodic - how to interpret the results of measurement; methodology - the program of the control/inspection and testing programmes: localities to conduct the tests, how often, and to follow evolution of test results with the aim of acting before a failure occurs. Such methodology should be based on the use of specimen-free nondestructive method of the inspection (control), which could be used successfully at all stages of life cycle of the equipment: manufacturing, construction, installation of NPP, operation and during the NPP operation through integration into the Plant Life Management (PLiM) programme [1]. It will facilitate a real picture of change (degradation) of a SSC material’s condition in the zones subjected to the harschest stressors (neutron irradiation, erosion-corrosion/flow, thermal fatigue, vibration etc). Currently, there are various approaches used in the world to follow NPP ageing degradation, but until now, no specific methodology is used that could supply all the necessary information [2]. Therefore, there is no way to use various results. Thanks to considerable advances over the last 20 years or so, the science of hardness testing offers an elegant, non-destructive way to obtain vital materials properties — even in-situ on operating SSC [3–6]. In particular, the material’s elastic-plastic condition may be measured, giving indications on tensile yield stress elevation due to hardening and also loss in ductility. The work-hardening index may be easily obtained, giving information on the ability of the material (e.g. pressure vessel steel and weld) to deform plastically without brittle fracture. Taking into account the experience of the Center of Material Science and Lifetime Management Ltd. (CMSLM Ltd.) in the use of methods of hardness testing for the inspection of the equipment of NPP of Russian manufacture in Russia, Germany, Czech, Slovakia, Bulgaria [7], and also similar successful works in this direction in USA (Oakridge) [8], to Czech (NRI Rez) and other countries, it can be seen that the most promising direction in the field of specimen-free inspection of mechanical properties by use of hardness and hardness-related characteristics is use of the kinetic indentation method (KIM, ABIT). This method is based on recording the process of elastoplastic deformation caused by the indentation of a ball indenter. This method allows one to obtain, besides hardness values, tensile properties, elongation, work hardening coefficient, true-stress/true strain diagrammes which normally required the destructive testing of small specimens. However, till now there is no universal method of interpreting the information obtained, although it is generally known that irradiation causes a loss in ductility and increase in hardness and lowering of the work-hardening coefficient. Thus, it is necessary to develop a uniform methodology of using KIM, ABIT with reference to the inspection of materials which will allow to unify the inspection of materials of various classes of the equipment of NPP over all stages of life cycle. With the purpose of introduction of such a methodology it is necessary to develop and realize the program in the frames of IAEA with the above name.


2020 ◽  
Author(s):  
S. Venkatarajan ◽  
A. Athijayamani ◽  
B. V. Bhuvaneswari ◽  
R. Ganesamoorthy

2018 ◽  
Vol 941 ◽  
pp. 1950-1955
Author(s):  
Ludovic Ropars ◽  
Moukrane Dehmas ◽  
Elisabeth Aeby-Gautier ◽  
David Tricker ◽  
Dominique Schuster ◽  
...  

A Ti-3Al-2.5V matrix composite reinforced with 8.5 vol.% TiB was produced using a powder metallurgy route. Processing included the mechanical alloying of Ti-3Al-2.5V and TiB2 powders and Hot Isostatic Pressing (HIP) of the resultant composite powders, to produce a dense billet. These billets were subsequently extruded and/or subjected to various Conversion Heat Treatments (CHT), to complete the transformation of the TiB2 particles into TiB needles. The CHT was performed either before or after extrusion. Microstructures and tensile properties of the materials at each stage of the processing routes were investigated and compared to those of a non-reinforced Ti-3Al-2.5V material, manufactured by the same powder metallurgy route. It has been demonstrated that the processing routes have a great impact on the mechanical properties, through modifications of the matrix and reinforcement characteristics. Well-chosen processing routes lead to more ductile composites, though this gain in ductility leads to slightly lower stiffness and strength values. This study clearly demonstrates the possibility to produce, at an industrial scale, a ductile version of a highly reinforced titanium matrix composite, showing important application potential.


Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 156 ◽  
Author(s):  
Lu Xie ◽  
Haojie An ◽  
Chenwei He ◽  
Qin Qin ◽  
Qing Peng

Carbon honeycomb (CHC) has great application potential in many aspects for the outstanding mechanical properties. However, the effect of both defects and temperature on the mechanical properties are far from reasonable understanding, which might be a huge obstacle for its promising applications as engineering materials. In this work, we investigate the effect of vacancy-type defect, which is inevitably exists in material, on the mechanical properties of CHC via reactive molecular dynamics simulations. The mechanical strength is anisotropic and decreases with the increasing temperature. CHC yield in cell axis direction since the break of C–C bonds on the junction. Vacancies weaken CHC by reducing the strength and failure strain. The effect of single vacancy on strength of CHC becomes more obvious with reducing temperature and is sensitive to the location and bonding of the vacancies. The maximum reduction of strength in cell axis direction is with vacancy on the middle of the wall of CHC where sp2 bonds are removed. The strength is reduced by 8.1% at 500 K, 11.5% at 300 K and 12.8% at 100 K. With 0.77% defect concentration, the strength reduces 40.3% in cell axis direction but only 18.7% in zigzag direction and 24.4% in armchair direction.


Sign in / Sign up

Export Citation Format

Share Document