Papers by Keyword: Test Procedure

Abstract: One of the factors hindering the normal development of additive construction technologies is the lack of reasonable methods for evaluating the suitability of mixtures for printing. This makes it almost impossible to compare remotely the compositions of different developers, makes it difficult to develop equipment and regulatory documentation, without which it is impossible to complete industrial production. The paper considers the feasibility of introducing the concept of “printability” of compositions and “rheological technological index of mixtures” as a numerical indicator for its evaluation. The design of the device for determining the rheological technological index is described. The developed device has a low cost of production, is linked to standard equipment of construction laboratories and emulates the main types of effects on the mixture during the extrusion process. The effective method for ensuring the printability of fine-grained concretes is considered based on the joint use of traditional plasticizing additives with entrained agents – foaming agents for cellular concretes. The effect of these additives is realized at different scale levels (micro-and mesolevels (cement paste) – traditional superplasticizers; macro-level (fine aggregate) - entrained agents), which together provides high rheological technological indices and effectiveness of mixtures with increased amounts of sand, low W/C ratios and small dosages of these additives. The use of additional mineral or organic rheology modifiers that increase the cost of the mixture is not required in this case. The structural features and basic properties of the developed composites are studied, allowing making comparisons with the solutions of other developers, assessing the prospects of the proposed method of ensuring printability, and outlining directions for its further improvement.

Abstract: This paper summarizes the test method of ice-phobic coating adhesion strength and the progress in coating material. Ice adhesion strength of several commercial ice-phobic coatings were tested for Pratt & Whitney, and result indicated that reformative silicone R-2180 show significantly improved reduction in ice adhesion when compared to several different commercially available silicone-based ice-phobic coatings. It would be valuable in future studies to measure the surface energies of the several materials tested to determine any correlation between the ice adhesion and surface energy of the coating.

Abstract: This paper presents procedures and standards to test tactile and optical microsensors and micro-computed tomography (CT) systems. The tests are similar to the established tests for classical coordinate measuring machines and assess local and global sensor characteristics. For this purpose, adequate and miniaturized reference standards were manufactured, calibrated and tested. In addition, task-specific reference standards have been realized to determine special sensor characteristics such as the maximum slope angle measurable by optical sensors or specific errors of tactile-optical microprobes measuring deep microholes.

Abstract: This paper describes new structure of specimen easy to manipulate, align and grip a thin-film and test machine for a fatigue test. High cycle fatigue test has been performed on tensile type specimen of Al-3%Ti alloy using the newly developed fatigue test machine. The material used in this study was Al-3%Ti thin film, which was used in RF MEMS switch. The structure of the suggested specimen has two holes and several bridges. The holes at centre of grip end are able to make alignment and gripping easy. The bridges are to remove the side support strip easily and extract specimen from wafer without sawing. The test machine was developed using the voice coil of speaker. The new tensile loading system has a load cell with maximum capacity of 0.5N and a non-contact position measuring system based on the principle of capacitance micrometry with 0.1nm resolution for displacement measurement. Fatigue tests was performed on 7 specimens. The thickness and width of the thin film of specimen are 1.0μm and 150μm, respectively. The fatigue strength coefficient and the fatigue strength exponent of Al-3%Ti alloy micro-sized specimen are determined to be 164MPa and -0.01322, respectively