scholarly journals Mathematical modeling of the percussion mechanism with a single impact energy increase

2021 ◽  
Vol 1061 (1) ◽  
pp. 012042
Author(s):  
V G Zedgenizov ◽  
D V Kokourov ◽  
T A Senotrusova
Keyword(s):  
Mathematical Modeling ◽  
Impact Energy ◽  
Energy Increase ◽  
Single Impact

Full-Scale Testing and Performance Evaluation of Rockfall Concrete Barriers

2015 ◽  
Vol 2522 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Anil Patnaik ◽  
Abdisa Musa ◽  
Srikanth Marchetty ◽  
Robert Liang
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Loading ◽  
Structural Integrity ◽  
Precast Concrete ◽  
Absorption Capacity ◽  
Full Scale ◽  
Energy Absorption Capacity ◽  
Single Impact ◽  
Concrete Barriers

Rockfall hazards are present throughout the state of Ohio. The Ohio Department of Transportation (DOT) employs Test Level 3 standard concrete barriers along the edges of roadways to contain rockfalls in high-risk areas. The performance of these barriers under impact from rocks on the ditch side and their effectiveness for rockfall catchment are relatively unknown. Full-scale impact tests were performed on concrete barriers to simulate the effects of impacts from rocks of various sizes and shapes. Numerous impacts were made at different sections and levels of the barriers to test their structural integrity and energy absorption capacity. The results from this study revealed that 32-in.-high precast concrete barriers with current Ohio DOT details had an impact energy absorption capacity of up to 24 kJ under a single impact. The corresponding energy absorption capacity of 42-in.-high cast-in-place concrete barriers was about 56 kJ under a single impact. Moreover, these barriers experienced severe cracking and spalling of concrete under impact loading. Several design modifications were studied in this test program. These modifications included reducing the spacing of rebars and rebar sizes, using welded wire fabric, and using different types of fibers in the concrete. The tests conducted on the modified concrete barriers showed an impact energy increase of more than 100% with the modifications suggested in this study. Barriers made from the modified designs also experienced significantly reduced extent and severity of cracking and a reduction in spalling and splashing of concrete under impact loading.

High Velocity Compaction of 316L Stainless Powder

2010 ◽  
Vol 44-47 ◽  
pp. 2993-2997 ◽  
Author(s):  
Jin Chen ◽  
Zhi Yu Xiao ◽  
Chao Jie Li ◽  
San Cai Deng ◽  
Tung Wai Leo Ngai ◽  
...  
Keyword(s):  
Impact Energy ◽  
High Velocity ◽  
Delay Time ◽  
Green Density ◽  
Single Impact ◽  
Impact Process ◽  
Ejection Force ◽  
High Velocity Compaction ◽  
Total Impact ◽  
Double Impact

High velocity compaction technology was used to press 316L stainless powders. Effects of impact times on stress wave, green density and ejection force were analyzed. It was found that under the same total impact energy, the first loading time and the actuation duration of the second impact in double impact process were longer when compared with single impact process, while the first delay time was shorter. Furthermore, the green density of compacts prepared by double impact was greater than that prepared by single impact, but no obvious variation in maximum ejection force can be observed between single impact and double impact process.

Microstructure and Mechanical Properties of G17CrMoV5-10 Cast Steel After Regenerative Heat Treatment

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Grzegorz Golański
Keyword(s):  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Strength Properties ◽  
Optimum Combination ◽  
Austenitizing Temperature ◽  
Energy Increase ◽  
Regenerative Heat ◽  
Term Operation

This paper presents the results of a research on the influence of regenerative heat treatment on microstructure and properties of a cast steel after long-term operation at the elevated temperature. The material under investigation was G17CrMoV5-10 cast steel taken out (in the form of a section) from an internal frame of steam turbine serviced for about 250,000 h. Performed research has proven that through the microstructure degradation long-term service contributes to an embrittlement and decrease in yield strength and tensile strength. The heat treatment, however, contributes to an impact energy increase regardless of the applied parameters (cooling rate). It has also been established that the optimum combination of strength properties and impact energy is ensured by the microstructure of high tempered bainite, whereas low strength properties and impact energy were obtained for the microstructure, which was slowly cooled from the austenitizing temperature, i.e., the ferritic-bainitic-ferritic microstructure.

A new method for testing pile by single-impact energy and P-S curve

2004 ◽  
Vol 17 (S1) ◽  
pp. 138-149
Author(s):  
Zhao-yong Xu ◽  
Yong-kang Duan ◽  
Bin Wang ◽  
Yi-li Hu ◽  
Run-hai Yang ◽  
...  
Keyword(s):  
Impact Energy ◽  
New Method ◽  
Single Impact ◽  
S Curve

FLEXURAL STRENGTH AND IMPACT ENERGY OF MICROFIBRIL BAMBOO FIBER REINFORCED ENVIRONMENT-FRIENDLY COMPOSITES BASED ON POLY-LACTIC ACID RESIN

2011 ◽  
Vol 25 (31) ◽  
pp. 4195-4198 ◽  
Author(s):  
SUJITO ◽  
HITOSHI TAKAGI
Keyword(s):  
Lactic Acid ◽  
Flexural Strength ◽  
Impact Energy ◽  
Bamboo Fiber ◽  
Poly Lactic Acid ◽  
Flexural Properties ◽  
Green Composites ◽  
Energy Increase ◽  
Environment Friendly ◽  
Biodegradable Poly

Environment-friendly or "green" composites (GCs) made from micro-fibril bamboo fiber (BF) and biodegradable poly-lactic acid (PLA) resin were fabricated using a hot-pressing methods. The effect of BF content on the flexural properties and impact energy of the GCs was investigated. The results show that the flexural properties and impact energy of the GC samples are tremendously affected by the addition of BF. Both the flexural properties and impact energy increase with increasing the BF content up to 40% and then decrease with BF contents less or more than 40% by mass. This was because of the existence of internal defects such as voids was observed for the GC samples reinforced with less or more than 40% mass of BF.

scholarly journals Theoretical and empirical methods of estimating energy and force characteristics of impact wrenches

2019 ◽  
Vol 97 ◽  
pp. 05028
Author(s):  
Anatoliy Drozdov
Keyword(s):  
Impact Energy ◽  
Correct Choice ◽  
Strength Analysis ◽  
Production Environment ◽  
Empirical Methods ◽  
Indirect Determination ◽  
Single Impact ◽  
Threaded Connections ◽  
Design Values

The Article represents theoretical and empirical methods of estimating the characteristics of impact wrenches when torquing specific threaded connections and in fixed anvil mode. They allow addressing the following issues: indirect determination of single impact energy in production conditions based on the proposed technique of estimating specific characteristics of stiffness and impact threshold of the wrenches, which are used to obtain base of the initial design values of the mathematical model. These methods and the techniques developed based on them allow for determination of single impact energy both in laboratory and production environment, which is important at the stage of tool creation as well as during its operation in order to reasonably develop the size range of impact wrenches, carry out strength analysis of their striking mechanisms and choose a proper tool for a specific range of threaded connections. The correct choice of the tool can make installation procedure much more efficient due to the reduced time for assembly and ability to control torquing tightness of threaded connections. In hydrotechnical construction a significant amount of work falls on assembling threaded connections in the use of metal structures, products, and in used construction equipment.

Novel Design and Comparison of Structural and Modal Analyses of Auxetic Geometry versus Honeycomb Geometry

2021 ◽  
Vol 36 (4) ◽  
pp. 398-402
Author(s):  
U. Kemiklioğlu
Keyword(s):  
Tensile Strength ◽  
Modal Analysis ◽  
Impact Energy ◽  
Ansys Software ◽  
Energy Increase ◽  
Auxetic Structures ◽  
Lateral Displacements ◽  
The Impact ◽  
Novel Design ◽  
Auxetic Structure

Abstract Auxetic structures are popular, since they have many applications in defense, textile and sport industries. The advantages of providing comfort and protection to people for the impact energy increase the usability of auxetic structures in these areas. Within the scope of this study, two structures were designed as honeycomb and auxtetic structures with lateral displacements in opposite directions. The auxetic and honeycomb structures were modeled in Ansys software by keeping the boundaries of these two structures close to each other. Structural and modal analysis were applied to these structures and the auxetic structure gave better results in terms of the tensile strength.

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

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