Papers by Keyword: Material Property

Abstract: EPS thermal insulation system is one of the wider applications of exterior insulation system in the area of North China. In engineering applications, it is extremely important to improve the thermal insulation engineering quality to familiar with the structure principle, strengthen strict re-inspection of the material properties , standardized operation and fine construction, but also conducive to ensure its energy-saving effect and durability.

Abstract: EPS thermal insulation system is one of the wider applications of exterior insulation system in the area of North China. In engineering applications, it is extremely important to improve the thermal insulation engineering quality to familiar with the structure principle, strengthen strict re-inspection of the material properties , standardized operation and fine construction, but also conducive to ensure its energy-saving effect and durability.

Abstract: A new integrated system consisting of a testing machine, denominated Diaptometro, and of an algorithm for metallic materials identification via instrumented spherical indentation testing is presented. The identification is carried out by analyzing the experimental load – penetration depth curve ( curve) from shallow indentation tests, thus preventing any contact condition effects in the material properties estimation. Accuracy in the experimental data collecting and the curve representation were recognized to be the key factors at the basis of reliable and accurate estimations. A new equipment with accuracies of 0.075% and 0.1% for the penetration depth and indentation load respectively was specifically built-up, whereas a four-terms power expansion is proposed for modeling the curve in the identification procedure. Experimental validation campaigns confirm the effectiveness of the adopted solutions.

Abstract: Avian feather is the outstanding protein fiber structure that still lacks an interpretation generally acceptable in any detail. In this paper, asio otus feathers were morphological represented and their barbs were mechanical characterized by a developed micro-tensile tester with a load resolution of 0.25 mN and a displacement resolution of 10 nm. With a tensile loading speed at 0.02 μm/s, Young’s modulus of the flight feather barbs with length of 1450-1900 μm was calculated to be 3.13-3.66 GPa, higher than 1.47-2.04 GPa for the down feather barbs with length of 520-710 μm. It is concluded that the asio otus’s flight feathers on its wing and tail are more rigid than the down feathers on its body.

Abstract: NCFs (Non-Crimp Fabrics) infused with epoxy resin are popular in the design of wind turbine blades and other complex systems due to their ability to conform to complex shapes. Past work in the development of a combination beam-shell modeling approach to simulate the forming of NCF composites has been demonstrated to capture the change in the orientations of the yarns during a forming process. The structural performance of these manufactured blades is often analyzed using finite element simulations that consider the material properties of the fibers and of the resin based on the rule of mixtures and orthotropic shells where the model is sectioned into zones that account for changes in the material properties due to variations in the orientations of the lamina and number of layers. With the availability of the beam-shell model, the use of zones can be removed if the individual contributions of the yarns (beam elements) and resin (shell elements) can be characterized and the orientations of the yarns resulting from a forming simulation can be used to account for the variations in the material properties of the composite throughout the blade. This research uses a combination of static flexure tests and impact modal tests to ascertain the material properties of the fibers and resin in a unidirectional and biaxial non-crimp fabric laminate plates. The material properties are used in a finite element model of the plate and the model is analyzed in flexure and in a free-free modal configuration to compare to experimental results. Two different approaches are used in the commercially available software Abaqus to model the plate. One approach uses a combination of beam and shell elements to represent the fibers and the resin, respectively. The other approach uses orthotropic shell elements to capture the unbalanced behavior of the fiber/resin composite. The beam/shell modeling approach better represents the overall behavior of a single-layer plate and can be extended to consider multiple plies.

Abstract: The last decade has shown an expanding interest towards incremental sheet forming (ISF). The present paper focuses on a wide variety of materials used in ISF with emphasis on material behavior and post forming properties. Material behavior knowledge is essential for improving process control and accuracy, post forming properties are essential for introducing ISF for wider industrial use. Included in the study are: a ferritic and four austenitic stainless steel grades, a deep drawing steel, as well as copper and silver. The two latter materials have been widely used for crafted products trough centuries and still have their place in high-end products. The suitability of the different materials for ISF is studied and compared. A comprehensive testing procedure is performed to gain information about behavior during and properties after deformation. The material property evolution is also compared to other forming methods to further enhance understanding of the process. The materials can be divided into stable and metastable materials. Stainless steels are an increasingly important class of alloys that are widely used in industry today. The structure of austenitic stainless steels is metastable which may lead to phase transformation. Strain induced martensite phases can form during plastic deformation of these steels. The formation of martensite affects significantly their mechanical behavior by enhancing the work hardening. Transformation impedes the property prediction as it is linked to the process conditions which may vary during forming. The stable materials lack phase transformation but show both diverse and similar material property evolution as a result of ISF.

Abstract: The pear-shaped needle is the finishing tool of spinneret micro-holes. The material of pear-shaped needle is cemented carbide having high wear resistance and toughness. The detection system of pear-shaped needle geometric parameter studied is based on machine vision technology and material properties. The hardware of detection system consists of the IPC, horizontal movement platform, precision rotary axis, the servo motor, image collection card, CCD, industrial lens and LED light source. The software of detection system uses Labview as the development platform. The experiment shows that the detection accuracy of maximum diameter of the pear-shaped needle is up to ± 1μm.

Abstract: The paper provides a review about the corrosion ,corrosion protection and material properties of support structures for offshore wind turbines. Firstly, the current state of corrosion protection research on offshore wind turbines is discussed. Secondly, types of the marine corrosion environment, corrosivity categories and material properties are summarized in a systematic way.Finally, practical solutions to the corrosion protection of support structures, including cathodic protection ,coatings and silane impregnation, are discussed.

Abstract: The designing level of oil and gas well hole structure and application in superdeep well with analysis of material properties play a key role in the expected production target to superdeep oil and gas wells. This paper introduces the hole structure of standard casing size series, main problems in superdeep wells with analysis of material properties, and solving means such as: using liner as production casing, cementing under small clearances of borehole-casing annulus and intermediate casing-production casing annulus, reaming and close clearance hole structure, analysis of material properties and so on. By application, the study above has a good practicality.

Abstract: A new material of cation platinum (II) complex has been synthesized and characterized. The new material binding properties with human telomeric G-quadruplex DNA (G₄-Htel DNA) and ct-DNA were examined by UV-Vis and CD spectroscopic methods. The results showed that complex exhibited higher binding affinity and binding intensity to G₄-Htel DNA (up to K_b = 1.54×10⁶ M^-1) and with selectivity (up to 11-fold) over duplex DNA. The CD results suggests the antiparallel structure of G-quadruplex can remain stable in the presence of platinum complex and the complex may bind to DNA by intercalation mode.