Ultrasonic autofocus imaging of internal voids in multilayer polymer composite structures

Ultrasonics ◽  
2022 ◽  
Vol 120 ◽  
pp. 106657
Author(s):  
Kaipeng Ji ◽  
Peng Zhao ◽  
Chaojie Zhuo ◽  
Mu Chen ◽  
Jian Chen ◽  
...  
Author(s):  
Akarsh Verma ◽  
Naman Jain ◽  
Avinash Parashar ◽  
Vinay K. Singh ◽  
M. R. Sanjay ◽  
...  

2016 ◽  
Vol 52 (11) ◽  
pp. 1-5 ◽  
Author(s):  
Dibyajat Mishra ◽  
P. Markondeya Raj ◽  
Joel Tishler ◽  
Teng Sun ◽  
Erik Shipton ◽  
...  

Author(s):  
М. Н. Журибеда

It is shown that the development of the concept of metrological support for the creation of composite structures of aircraft aggregates of the transport category and their support at all stages of the existence of an aircraft should be based on the formation of a complex criterion for the effectiveness of the use of polymer composite materials. It is noted that the effectiveness of a structure made of polymer composite materials is provided by various methods, methods and technical means of metrology. The structure of a complex of studies aimed at developing the concept of metrological support is discussed, the first point of which is to analyze the types of metrological characteristics and the scope of work to determine them at the main stages of the existence of composite structures of aircraft aggregates of the transport category. Based on the analysis of numerous publications on the problem of metrological support of the main stages of creating technical products, the main types of measurements of the metrological characteristics of composite structures of aircraft aggregates of the transport category have been established, and the composition of the nomenclature of works on metrological support of the main stages of the existence of these structures has been determined. 12 main types of measurements of parameters have been identified, on which the whole variety of production physical quantities and the description of the properties and characteristics of structures of aircraft aggregates made of polymer composite materials are based. The composition of the main works on the metrological support of the four stages of the existence of the aircraft is revealed: design, production, operation and disposal of composite structures formed into systems of sequential blocks for performing these works. It is shown that the tasks of metrological support at the facility manufacturers should be solved during the technological preparation of serial production and testing of the installation series of products, and also take into account the peculiarities of aircraft operation and disposal of composite structural elements in terms of work safety and economic efficiency of their results. An enlarged sequence has been established for organizing work on metrological support for measuring the properties of composite structures of aircraft aggregates at aviation enterprises. The results presented in the first approximation provide a solution to practically important aspects of the problem under discussion.


2021 ◽  
Vol 29 (6) ◽  
pp. 28-39
Author(s):  
A. N. Garashchenko ◽  
A. V. Vinogradov ◽  
I. Z. Dashtiev ◽  
N. V. Kobylkov ◽  
S. A. Terekhov

Introduction. Coiled MBOR basalt fiber material is used to demonstrate the potential of research into the fire protection of structures using a radiant heat test facility. Research methods. A set of high-power halogen lamps is used to simulate a high temperature impact. The heating intensity is adjusted by changing the voltage applied to the lamps, and it is controlled by the thermocouples that record the temperature of the heated surface of a fire proofing material. The studies have proven efficient for various types of fire proofing and various structures. They are especially relevant in providing rational fire protection of polymer composite structures having relatively low thermal resistance (80…120 °С) due to the fact that they are rarely tested in fired furnaces. Results and discussion. Several options of multilayered MBOR-20F fire proofing were tested. Dependences between time, on the one hand, the surface temperature of protected elements (200 × 300 × 20 mm polyurethane plates), and the temperature between the layers of the fire-proofing material, on the other hand, are presented under standard temperature conditions. Fire protection efficiency improvement by PLAZAS fire-resistant adhesive compound, applied between MBOR layers, is demonstrated. This fireproofing method is applicable not only to metal structures. It demonstrates high fireproofing properties and has a strong potential if applied to fireproof polymer composite structures and products. The measurements, taken by thermocouples in the course of a session of tests, can be used to estimate the thermophysical properties of fireproofing materials exposed to high temperatures, which are rare in most cases, although they are necessary for a thermal analysis. It is demonstrated that similar experiments can also be carried out at nonstandard heating temperatures (for example, when the combustion of fossil fuels is imitated). Conclusions. Experiments, conducted using the radiant heat test facility, and thermal engineering calculations allow to accelerate the selection of the optimal fire protection option and identification of the fireproofing thickness. Moreover, this method allows to reasonably minimize the number of costly fired furnace tests using fullscale samples of fireproofed structures and products.


2012 ◽  
Vol 89 ◽  
pp. 216-218 ◽  
Author(s):  
Zhengdao Wang ◽  
Weibin Song ◽  
Liaoliang Ke ◽  
Yuesheng Wang

2019 ◽  
Vol 30 (17) ◽  
pp. 2639-2647
Author(s):  
O-Hyun Kwon ◽  
Jin-Ho Roh

A sandwiched morphing structure is developed using an Origami-inspired shape memory dual-matrix composite core and shape memory polymer composite skins. The geometric parameters of the morphing structure are designed to have a zero Poisson’s ratio. In addition, an analytical model is developed to analyze the three-dimensional morphing structure easily. The shape memory dual-matrix composites are fabricated with woven fabrics based on the shape memory polymers, and an epoxy matrix is used to ensure a flexible and shape-recoverable structure. The shape recoverability of the shape memory polymer composite skins is verified by measuring the shape recovery ratio at various temperatures. Based on the tensile tests for the shape memory polymer composite skins and shape memory polymer hinges, it is found that the morphing structure can be highly flexible depending on temperature. Finally, the bending and shape recovery behaviors of the morphing structure are demonstrated.


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