Experimental Measurement of Strain and Deflection in a Uniformly Loaded Simply Supported Composite Panel

1978 ◽  
Author(s):  
Franklin D. Barca
2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.


2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.


2014 ◽  
Vol 4 (4) ◽  
pp. 26-33
Author(s):  
P.Deepak Kumar ◽  
◽  
Ishan Sharma ◽  
P.R. Maiti ◽  
◽  
...  

1986 ◽  
Vol 18 (11) ◽  
pp. 131-140
Author(s):  
Edmundo Garcia Agudo ◽  
Jose Leomax dos Santos

The final disposal of sewage using submarine outfalls has become an actual solution for coastal cities all over the world. In order to get the best results it is necessary to carry out specific studies for the proper design of the outfall. Dilution and decrease in bacterial concentrations are two key aspects for the design. Radioisotope tracers have been used extensively in studies performed in some Brazilian waterbodies where outfall systems exist or are to be installed. As far as dilution measurement is concerned, both point and continuous radiotracer injections can provide useful results. The T90 measurements can be better accomplished using a combined tracer technique for sampling the sewage field, using the radiotracer for dilution measurement and rhodamine B as a visual aid. Typical results of dilution measurement using both techniques mentioned, as well as a summary of T 90 results obtained for the Santos, Fortaleza and Maceió outfalls are presented.


Sign in / Sign up

Export Citation Format

Share Document