Determination of the elastic modulus of the interphase zone in a layered polymer composite material

2014 ◽  
Vol 0 (2) ◽  
pp. 53-55
Author(s):  
V.S. Erasov ◽  
◽  
A.I. Makarycheva ◽  
2020 ◽  
Vol 17 (35) ◽  
pp. 599-608 ◽  
Author(s):  
Alexander A. OREKHOV ◽  
Yuri A. UTKIN ◽  
Polina F. PRONINA

One of the significant innovative technologies is the creation of large-sized structures that work for a long time in space and meet stringent restrictions on overall mass characteristics. Among these structures, in the first place, is the section of bearing truss (BT). This article presents the results of experimental studies of sectors of load-bearing trusses of mesh design for compression. Recently, composite mesh cylindrical shells are used as spacecraft housings. The mesh shell is a supporting structure to which the instruments and mechanisms of the spacecraft are attached. The truss section is made of cross-linked polymer composite material with carbon fibers. The objective of the tests is to confirm the possibility of creating a lightweight mesh construction using a carbon fiber reinforced polymer composite material. To achieve this goal, the authors were assigned the following tasks: selection of carbon filler of polymer composite materials (PCM); selection of PCM binder; determination of the degree of carbon fiber reinforcement; choice of the number and orientation paths of spiral ribs, number of ring ribs and the sizes of individual ribs. As a result of the research, the calculated indicators for ensuring the bearing capacity and stiffness under the application of axial compressive load were obtained. At the same time, with the determination of bearing capacity, the deformation characteristics of the structure were twice determined in order to confirm their repeatability, as well as linear nature of the dependence of axial and radial deformations as a result of the applied load.


2019 ◽  
Vol 85 (4) ◽  
pp. 33-39
Author(s):  
Victor V. Murashov ◽  
Valery M. Aleksashin ◽  
Konstantin S. Mishurov

The results of studying the efficiency of the laser-acoustic method of ultrasonic testing in determination of the degree of polymerization of the matrix of polymer composite material (PCM) are presented. We have studied the PCM samples used for manufacturing integrated structures. It is shown that excessive degree of polymerization of the preformed blanks leads to a decrease in the strength of connection of the structural elements and precludes obtaining the desired shape and geometric dimensions of the product. We developed fundamentally new diagnostic parameters, which are characterized by high reliability and accuracy of determination. To forecast sample curing regimes with given values of the degree of transformation, the reaction kinetics was analyzed using differential scanning calorimetry Experimental results used for calculation of the kinetic parameters were obtained on a thermoanalytical complex DSC 1 (Switzerland). The kinetic parameters of polymerization and degree of binder curing in plastics were determined by the thermal effect of the reaction. It is shown that when determining the degree of polymerization of a PCM matrix by an ultrasonic method (laser-acoustic method of exciting ultrasonic vibrations), the product of attenuation of the bottom signal of longitudinal ultrasonic vibrations by the signal round-trip time and energy of the structural noise (thus taking into account the porosity of the material), can be used as reliable parameters of diagnostics. The proposed method provides higher accuracy compared to other methods used for control of the degree of polymerization.


Author(s):  
Tamara Storodubtseva ◽  
B. Bondarev ◽  
Eduard Chernikov

The article deals with the problem of finding the necessary properties of a polymer composite material for the production of sleepers, which is solved by an experimental statistical method. Solving this problem of multiple-criteria optimization, the necessary values of the mass coefficient and the bend of the railway sleeper were determined in natural and coded scales, respectively. The obtained properties of the material for a polymer composite sleeper are selected by reducing the parameters to the minimum permissible values that characterize the stress-strain state of the structure. Optimising the task of finding optimal properties of a sleeper structure made of composite material using this method, we obtain properties of the sleeper that can vary. The response of functions that depend on variable factors is presented in the form of second-order polynomial models in which the coefficients were determined by experiment planning methods. The bending coefficient is necessary to determine the elastic modulus of a polymer-composite sleeper in the longitudinal direction. The mass value is determined from the operating conditions in the railway track block and is 145-154 kg, the value of the elastic modulus in the longitudinal direction is 6200-7600 MPa, and in the transverse direction-not less than 1000 MPa.


2019 ◽  
Vol 0 (2) ◽  
pp. 22-28
Author(s):  
A.M. Kudrin ◽  
◽  
O.A. Karaeva ◽  
K.S. Gabriel’s ◽  
◽  
...  

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