Comparison of Residual Strength of Composite and Metal Structures after Ballistic Damage

2009 ◽  
pp. 72-72-20 ◽  
Author(s):  
JA Suarez ◽  
JB Whiteside
2020 ◽  
Vol 4 (97) ◽  
pp. 69-76
Author(s):  
IGOR N. SILVERSTOV

A stochastic approach has been developed to evaluate fatigue strength using elements of the fracture mechanics. The article presents a method for determining the initial parameters of statistical distributions. It also considers the method for constructing a fatigue curve for a component of any size and configuration with any given probability of failure.


2020 ◽  
pp. 68-77
Author(s):  
O.N. CHERNYKH ◽  
◽  
A.V. RBURLACHENKO

Recommendations are presented for solving issues that arise in the design and operation of tubular transport crossings of corrugated metal structures through spawning streams while ensuring the safety and natural reproduction of fish stocks. There are discussed the results of experimental studies of culverts made of metal corrugated pipes with a normal and spiral shape of corrugation the bottom of which is buried and filled with suitable granular material to the level of the natural channel of a small watercourse. It is established that when 10% of the area of the corrugated pipe is occupied by stone filling, its throughput is reduced by about 10-12%. Based on the review of the existing literature and the results of laboratory experiments, data is provided to estimate the values of the roughness coefficients of the composite cross-section of a single-point junction and directions for future research on culvert reclamation are outlined. Studying of the structure of the velocity distribution in culverts can lead to the improved conditions for fish passage without installing special structural elements in the transit path of the fish passage structure.


2019 ◽  
Vol 61 (7) ◽  
pp. 618-620
Author(s):  
Naveen Raj Visvanathan ◽  
Mohd Shukry Abdul Majid ◽  
Faisal Abrar Syamsul Bahri ◽  
Mohd Ridzuan Mohd Jamir ◽  
Mohd Afendi Rojan Arau

2018 ◽  
Vol 69 (9) ◽  
pp. 2563-2566
Author(s):  
Dan Dobrota

Mining equipment made of welded metal structures is strongly affected by the corrosion phenomenon due to the working conditions. Initial research has shown that the corrosion phenomenon is most pronounced in the area of cross-welded joints and welded T-shaped joints. In the researches, there was made a chemical analysis of the welded construction material used respectively of the new material and it was observed a reduction in carbon concentration in the material used, but also a substantial increase in the sulfur concentration compared to the new material. The pronounced corrosion of the metallic structure is influenced by the chemical composition change because the sulfur is a grafitizing and weakening element, and the decrease in carbon concentration causes a decrease in corrosion resistance. Also, the pronounced corrosion is due to the action of sulfurous acid (H2SO3) and hydrogen sulfide (H2S), elements that are present in the working environment of welded constructions. In order to achieve a reduction in the corrosion phenomenon, it is very important that the welded joints are made using the optimal parameters of the welding regime so as to obtain metallographic structure with finer granulations.


Author(s):  
S.E. Rudov ◽  
◽  
V.Ya. Shapiro ◽  
O.I. Grigoreva ◽  
I.V. Grigorev ◽  
...  

In the Russian Federation logging operations are traditionally carried out in winter. This is due to the predominance of areas with swamped and water-logged (class III and IV) soils in the forest fund, where work of forestry equipment is difficult, and sometimes impossible in the warm season. The work of logging companies in the forests of the cryolithozone, characterized by a sharply continental climate, with severe frosts in winter, is hampered by the fact that forest machines are not recommended to operate at temperatures below –40 °C due to the high probability of breaking of metal structures and hydraulic system. At the same time, in the warm season, most of the cutting areas on cryosolic soils become difficult to pass for heavy forest machines. It turns out that the convenient period for logging in the forests of the cryolithozone is quite small. This results in the need of work in the so-called off-season period, when the air temperature becomes positive, and the thawing processes of the soil top layer begin. The same applies to the logging companies not operating in the conditions of cryosolic soils, for instance, in the Leningrad, Novgorod, Pskov, Vologda regions, etc. The observed climate warming has led to a significant reduction in the sustained period of winter logging. Frequent temperature transitions around 0 °C in winter, autumn and spring necessitate to work during the off-season too, while cutting areas thaw. In bad seasonal and climatic conditions, which primarily include off-season periods in general and permafrost in particular, it is very difficult to take into account in mathematical models features of soil freezing and thawing and their effect on the destruction nature. The article shows that the development of long-term predictive models of indicators of cyclic interaction between the skidding system and forest soil in adverse climatic conditions of off-season logging operations in order to improve their reliability requires rapid adjustment of the calculated parameters based on the actual experimental data at a given step of the cycles.


Author(s):  
Rupesh Wadher

Examination of ongoing pathology in patient’s body is quite essential for a physician to calculate the estimation the dose of drug. But examination method mentioned in Ayurveda is incomplete without using the present concept of Aturaparijnana Hetu. With the help of Aturaparijnana Hetu the traditional methods of person understanding (the Dashavidha Pariksha) become more accurate and powerful. Aturaparijnaana Hetu gives standard of a person. In this way, examination method acquires the foundation; designed for grading. In short, person’s residual strength can be documented. These article is intended to highlight the research work through survey study that how can a group is identify by their respective Desha and their role in Dashavidha Pariksha. Dehabala and Doshabala are assessing by this methods.


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