scholarly journals Fatigue of the automobile structural materials in corrosive environment

2020 ◽  
Vol 164 ◽  
pp. 03039
Author(s):  
German Pachurin ◽  
Diana Goncharova ◽  
Gor Gevorgyan ◽  
Aleksey Filippov ◽  
Marya Mukhina ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Experimental Studies ◽  
Structural Materials ◽  
Operational Reliability ◽  
Machine Building ◽  
Materials Testing ◽  
Corrosive Environment ◽  
Fatigue Rupture ◽  
New Processing ◽  
Experimental Data Analysis

Operation of machines and equipment is accompanied by an impact produced by various types of loads leading to fatigue rupture of the structural materials. The most harmful are the vibration loads which in a corrosive environment increase the potential for a failure resulting in human casualties. Therefore, the task of ensuring the operating capability of machine elements and assemblies is one of the outstanding tasks for all industry sectors. In addition, the need for extending the service life and increasing the operational reliability is also determined by a relatively high cost of the machine structural materials and hardware items. Therefore, the execution of the experimental studies of the structural material fatigue features with a view to reduce the metal consumption, to establish new processing methods as well as to select a competitive material, are of the priority for the up-to-date machine building sector. The purpose of this article is to determine any fatigue behavior regularities in automotive materials which were pre-processed according to various technology types and modes and which were operating in a corrosive environment. The experimental data analysis has demonstrated that the longer the cyclic metal materials testing is run, the more sufficient is the decrease of the fatigue resistance of these.

Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Structural Materials ◽  
Fatigue Tests ◽  
Material Defects ◽  
Graphite Cast Iron ◽  
Ultrasonic Fatigue ◽  
Materials Used ◽  
Fatigue Failures

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.

Evaluation of High Cycle Fatigue Properties of Double Side Welded AISI 321 Plates Using GTAW Process for Pressure Vessels

2021 ◽  
Author(s):  
Mohan Kumar S ◽  
A. Rajesh Kannan ◽  
Pramod R. ◽  
Pravin Kumar N ◽  
Nallathambi Siva Shanmugam ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Fatigue Behavior ◽  
Fatigue Behaviour ◽  
Pressure Vessels ◽  
Fatigue Properties ◽  
Dendritic Microstructure ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Fatigue Rupture ◽  
Aisi 321

Abstract Titanium stabilized AISI 321 material (UNS S32100) is generally preferred in the pressure vessel industry as they are not sensitive to intergranular corrosion. In critical applications, the fatigue behaviour of weld seams are amongst the most stringent requirements. The microstructural characteristics and fatigue performance of double side welded AISI 321 plate having 6 mm thickness were evaluated in this work. AISI 321 was welded with Double side-gas tungsten arc welding (DS-GTAW) process. The fatigue behavior was examined under a loading ratio of 0.1 for two different specimens: Base metal (BM) and Weld metal (WM). Monotonic tensile results show the improved tensile properties of WM compared to BM samples. The fatigue strength of WM (332.6 MPa) was 25% higher than that of BM (265.7 MPa) specimen and is attributed to the increase in ferrite volume along with dendritic microstructure. The change in the fraction of low angle grain boundaries (LABs) and high angle grain boundaries (HABs) improved the tensile and fatigue properties. The stress amplitudes influenced the degree of striations in the BM and WM. Final fracture surfaces were characterized with dimples and micro-voids, revealing the ductile mode of fatigue fracture. The fatigue rupture surfaces of BM and WM samples at different stress regimes are discussed.

Systematic design of cantilever beams for muscle research

1977 ◽  
Vol 42 (5) ◽  
pp. 786-794 ◽  
Author(s):  
R. J. McLaughlin
Keyword(s):  
Elastic Modulus ◽  
Cross Section ◽  
Experimental Studies ◽  
Circular Cross Section ◽  
Design Procedure ◽  
Structural Materials ◽  
Thick Wall ◽  
Beam Parameter ◽  
Thin Wall ◽  
Cantilever Beams

Experimental studies of muscle contraction often involve difficult problems in the design of cantilever beams for movable levers, transducers, or mechanical supports. Equations are presented for the calculation of mass, inertia, stress distribution, strain, deflection curve, compliance, and resonant frequency of uniform or nonuniform cantilever beams made of structural materials of different density or elastic modulus. Formulas are listed for solid, thick-wall, and thin-wall uniform beams of rectangular and circular cross section. Physical properties including density, elastic and torsional moduli, stress and strain limits, thermal expansion coefficients, Poisson's ratio, and certain elastic-modulus-to-density ratios are tabulated for structural materials including common metals, glass, plastic, and wood. A graphical design procedure is presented based on a chart containing loci of constant beam parameter values as a function of beam length and height or diameter, for the simple geometries. The choice of structural material is discussed for design problems with typical constraints, and examples are given of the design of beams of nonuniform cross section. Methods for extending the design chart to other geometries and materials are included.

scholarly journals Cloud Phase Structure: Experimental Data Analysis and Parameterization

2006 ◽  
Vol 63 (2) ◽  
pp. 667-681 ◽  
Author(s):  
I. P. Mazin
Keyword(s):  
Soviet Union ◽  
Phase Structure ◽  
Former Soviet Union ◽  
Experimental Studies ◽  
Frequency Of Occurrence ◽  
Water Ice ◽  
Phase Index ◽  
Stratiform Clouds ◽  
Average Distribution ◽  
Experimental Data Analysis

Abstract In this article, the data collected over 6 yr of daily observations at a network of aircraft sounding (31 stations) in the former Soviet Union, and the data collected by Canadian researchers in field campaigns in the 1990s, are reanalyzed and compared with each other. To describe the cloud phase structure (CPS), the notion of the cloud phase index (CPI)3 is used; that is, the local mass fraction of the ice particles in the total (water + ice) water content. It is concluded that the average distribution of the (CPI)3 values in clouds depends mainly on the temperature, the cloud types, and the scale of averaging. If these characteristics remain unchanged the geographic and seasonal variations of the phase structure are small. It is shown that for averaging scales of the order of 100 m, the frequency of occurrence of liquid clouds [(CPI)3 = 0] varies from approximately 60% at 0°C to 5% at −35°C, and that of the ice clouds from about 5% to 60%. The frequency of occurrence of the mixed clouds only weakly depends on temperature, varying within 30%–40%. The dependence of the cumulative (CPI)3 distribution on temperature in the interval 0.1 < (CPI)3 < 0.7 is close to linear. For stratiform clouds (without going into further details) the coefficients of the linear parameterization are found as a function of temperature. Knowing the (CPI)3 distribution allows one to also estimate the humidity in clouds. The most urgent challenges for the experimental studies of the cloud phase structure are formulated.

Investigation on Seismic Behavior of Recycled Aggregate Concrete Structures under Dynamic Loadings

2013 ◽  
Vol 772 ◽  
pp. 149-155
Author(s):  
Chang Qing Wang
Keyword(s):  
Seismic Behavior ◽  
Fatigue Behavior ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Recycled Aggregate Concrete ◽  
Shaking Table ◽  
Frame Structure ◽  
Recycled Aggregate ◽  
Scale Model ◽  
Aggregate Concrete

Based on the ever finished investigations of physical and mechanical properties of recycled aggregate concrete (RAC), and a series of experimental studies on the durability, the fatigue behavior, mechanical behavior and the seismic behavior of RAC components. A full scale model of a one-storey block masonry structure with tie column + ring beam + cast-in-place slab system and a one fourth scaled model of a 6-storey frame structure, which are made of reinforced recycled aggregate concrete, are tested on a shaking table by subjecting it to a series of simulated seismic ground motions, and the seismic behaviors of the RAC structures were experimentally investigated. The dynamic characteristics and the seismic response were analyzed and discussed. The overall seismic performance of RCA structures are evaluated, the analysis results show that the recycled aggregate concrete structures with proper design exhibits good seismic behavior and can resist the earthquake attacks under different earthquake levels in this study. It is feasible to apply and popularize the RAC block masonry buildings less than 2 stories and the RAC frame buildings less than 6 stories in the region where the seismic fortification intensity is 8.

Effect of Fiber Diameter on Fatigue Strength of Fiber Reinforced Concrete and its Design

2011 ◽  
Vol 138-139 ◽  
pp. 810-815 ◽  
Author(s):  
Pang Jo Chun ◽  
Mitao Ohga
Keyword(s):  
Reinforced Concrete ◽  
Theoretical Model ◽  
Fiber Diameter ◽  
Design Method ◽  
Fatigue Behavior ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Stress Degradation ◽  
Fatigue Rupture ◽  
Number Of Cycles

This paper describes the effect of fiber diameter of fiber reinforced concrete (FRC) under fatigue behavior and its design method. Some researchers showed that the fatigue behavior of FRC is mainly governed by the bridging stress degradation, but little information is still available so far. We conducted fatigue tensile experiments of the FRC under constant strain amplitude first and the degradation of bridging stress was measured experimentally. Then, the micromechanics-based theoretical model is also developed, and the model is verified by the test results. The model accounts for the loss of fatigue ruptured fibers of which fatigue rupture is based on S-N relationships. The parametric study from the micromechanics-based theoretical model indicates that the best fiber diameter varies according to the number of cycles and strain level applied to the FRC specimen. The result suggests that we need to design FRC with considering the application and its loading conditions to utilize the capacity of FRC.

Study on the Fatigue Behavior of Carbon/Carbon Composites

2008 ◽  
Vol 385-387 ◽  
pp. 537-540 ◽  
Author(s):  
Xiao Ling Liao ◽  
Wen Feng Xu ◽  
Zhi Qiang Gao
Keyword(s):  
High Temperature ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Structural Materials ◽  
Carbon Composites ◽  
Made In ◽  
The Ideal

As the ideal candidates for high temperature structural materials, carbon/carbon (C/C) composites are no doubt involved in fatigue loading. Therefore, the study on fatigue behavior is meaningful. In this paper, the research on fatigue behavior of C/C composites was reviewed and the characteristic of fatigue behavior was summarized. Some viewpoints for further investigations for the study on the fatigue behavior of C/C composites are also made in this paper.

scholarly journals RESEARCH OF TECHNICAL CHARACTERISTICS OF NEW TYPES OF COUPLINGS

2020 ◽  
pp. 113-121
Author(s):  
Oleksii Tokarchuk ◽  
Yurii Polievoda
Keyword(s):  
Elastic Element ◽  
Rational Design ◽  
Experimental Studies ◽  
Bending Moment ◽  
Operational Reliability ◽  
Modern Technology ◽  
Operating Conditions ◽  
The Moment ◽  
Working Bodies ◽  
Moment Of Resistance

Dynamic loads that occur during the operation of existing couplings cause significant shock loads, which leads to rapid wear of the surfaces of the couplings and shortens the service life. Modern technology faces the task of improving the operational reliability of the working bodies and drives of machines. One way to solve this problem is to develop and use high-precision and low-dynamic safety couplings. In this regard, the question of developing new designs of safety couplings that reduce impact loads and increase the reliability and durability of machinery is relevant. The synthesis of structural and kinematic schemes of ball, cam and planetary safety couplings, the method of their calculation in combination with the nature of the change in the moment of resistance on the working body of the equipment. The article conducts a set of theoretical and experimental studies to determine their rational design, kinematic and dynamic parameters that will satisfy the operating conditions of machines and mechanisms. A force analysis of the elastic element (ring spring) was performed. The scheme of loading of an elastic element by two forces and other settlement schemes are constructed, namely: equivalent system; force diagrams for determining the load torque; force schemes for determining the unit moment; schemes of total bending moment; force schemes to determine the total unit moment. During static experimental studies of the developed ball safety couplings, the nature of their operation was established, the maximum torque at the two stages of operation of the couplings was determined and a comparative analysis between the results of theoretical and experimental studies was performed. The positive results of experimental researches of the developed coupling and theoretical positions which can be applied to a substantiation and a choice of rational parameters of the developed designs of couplings and their engineering designing were confirmed.

Sign in / Sign up

Export Citation Format

Share Document