Peculiarities of Strengthening of Spherical Composite Pressure Vessels with Thin Metal Shells Under Static and Dynamic Loads. Part 2. Dynamic Loading

Author(s):  
P. P. Lepikhin ◽  
V. A. Romashchenko ◽  
S. O. Tarasovs’ka
2021 ◽  
Vol 11 (19) ◽  
pp. 8973
Author(s):  
Kun Zhong ◽  
Wusheng Zhao ◽  
Changkun Qin ◽  
Hou Gao ◽  
Weizhong Chen

Roof rocks in coal mines are subjected to the combination of in situ stresses and dynamic stresses induced by mining activities. Understanding the mechanical properties of roof rocks under static and dynamic loads at medium strain rates is of great significance to revealing the mechanism of rock bursts. In this study, we employ the digital image correlation (DIC) technique to investigate the energy concentration and dissipation behaviors, failure mode, and deformation characteristics of roof rocks under combined static and dynamic loads. Our results show that both the static pre-stress and dynamic loading rate have significant effects on the uniaxial compressive strength of rock specimens. From the energy principle, when the static pre-stress is the same, both elastic strain energy density and dissipated energy density increase with increasing dynamic loading rate. The hazard of rock bursts increases with decreasing static pre-stress and increasing dynamic loading rate. At higher dynamic loading rates, more cracks are generated, and the failure becomes more violent. The crack initiation, propagation and coalescence processes are identified, and the failure mode is closely related to the evolution of the global principal strain field of the rock specimens.


2020 ◽  
Vol 164 ◽  
pp. 03025
Author(s):  
Elena Kurakina ◽  
Sergey Evtiukov

The present paper substantiates urgency of studies on early deterioration of pavement layers and on reasons entailing it. The aim was to investigate static and dynamic loads imposed on a road surface by vehicles in order to detect signs of early deterioration of pavement and understand its reasons. Certain tasks were set: to define diagnostic capacity for performing test works on road surface with the use of static and dynamic loading equipment; to carry out an elastic modulus analysis on the basis of static and dynamic loading tests performed; to assess strength properties of flexible pavement. The paper describes methods for determining strength properties of a road surface with the use of special static and dynamic loading equipment. The authors provide data on diagnostic capacity of tests of a pavement performed with the use of special testing equipment. The paper gives a list of potentials, advantages and fundamental features of the following units of equipment: apparatus for plate bearing tests, Dina-3M, UDN-NK, Dynatest apparatus. The main parameters of equipment for dynamic loading tests are provided. The results of both dynamic and static loading tests performed in Saint Petersburg and the Leningrad region are given. Deflection bowls and elastic modulus were determined. Coefficients of the dynamic elastic modulus being reduced to the static one were calculated. Strength properties of flexible pavement were assessed.


1940 ◽  
Vol 44 (349) ◽  
pp. 44-73
Author(s):  
Wilhelm Kuech

Laminated materials incorporating plastics seem to be especially well suited lor highly stressed aircraft components, by reason of their good strength properties. Paper, fabric and wood veneers treated with plastics on a phenolic basis were tested with regard to their strength, especially in bending, shear, absorbed energy in impact bending, notching strength and in their resistance against moisture. Further, the behaviour of compressed plastics was studied at different temperatures under static and dynamic loads. A part of the research was extended to pure phenol resin and to thermoplastics based on methacrylate and polyvinylchloride. The bonding properties of laminated compressed plastics were established. Concluding, some experiments relating to the practical manufacture of aeroplane components are communicated.


2016 ◽  
Vol 121 (1235) ◽  
pp. 73-94 ◽  
Author(s):  
A. Castrichini ◽  
V. Hodigere Siddaramaiah ◽  
D.E. Calderon ◽  
J.E. Cooper ◽  
T. Wilson ◽  
...  

ABSTRACTA recent consideration in aircraft design is the use of folding wing-tips with the aim of enabling higher aspect ratio aircraft with less induced drag while also meeting airport gate limitations. This study investigates the effect of exploiting folding wing-tips in flight as a device to reduce both static and dynamic loads. A representative civil jet aircraft aeroelastic model was used to explore the effect of introducing a wing-tip device, connected to the wings with an elastic hinge, on the load behaviour. For the dynamic cases, vertical discrete gusts and continuous turbulence were considered. The effects of hinge orientation, stiffness, damping and wing-tip weight on the static and dynamic response were investigated. It was found that significant reductions in both the static and dynamic loads were possible. For the case considered, a 25% increase in span using folding wing-tips resulted in almost no increase in loads.


2014 ◽  
Vol 1061-1062 ◽  
pp. 748-750
Author(s):  
Heng Chen ◽  
Ke Sheng Ma

For socked and non-socketed piles in the different mechanical behavior under static and dynamic loads, the paper use ABAQUS to model, simulate the pile , the soil interlayer thickness between the bottom of the pile and bedrock are 2m, 4m under vertical load and Earthquake, cushion cap, pile and pile soil stress situation found non-socketed piles when the soil interlayer thickness within a certain range, the composite pile small subside under dynamic, static loads, the non-socketed piles can better take advantage of the pile soil has a good seismic performance in the earthquake.


2022 ◽  
Vol 1049 ◽  
pp. 108-113
Author(s):  
Nikolay Kurlaev ◽  
Ahmed Soliman Mohamed Sherif ◽  
Nikolay Ryngach

Bellows are a cylindrical shell with a corrugated part, widely used in aviation engineering as a movable sealing element to balance pressure and temperature differences, which ensure continuous and accurate system operation. The use of bellows expansion joints provides reliable and effective protection of pipelines from static and dynamic loads arising from deformations and vibration. Welded-edge bellows are a popular choice for regulating and controlling fuel supply in aircraft devices. The ability of the compensator to perceive deformations is determined by its assigned operating time, which describes how many cycles, and with what amplitude, the bellows compensator perceives without damage. A method for stamping bellows from tubular billets by using magnetic-pulse field in rigid dies, including sequential shaping of corrugations by distributing the internal magnetic pressure with axial movement of the free end of a tubular billet, characterized in that the material of the tubular billet for shaping corrugations is selected in accordance with its relative elongation.


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