scholarly journals DEVELOPMENT OF THE TEST SYSTEM FOR MEASURING THE IMPACT ENERGY OF A HYDRAULIC BREAKER

2005 ◽  
Vol 2005 (6) ◽  
pp. 75-79 ◽  
Author(s):  
Jong-Won PARK ◽  
Hyoung-Eui KIM
Keyword(s):  
Impact Energy ◽  
Test System ◽  
The Impact

Impact Energy Measurement of a Hydraulic Breaker

2006 ◽  
Vol 326-328 ◽  
pp. 1669-1672
Author(s):  
Jong Won Park ◽  
Hyoung Eui Kim
Keyword(s):  
Construction Industry ◽  
Impact Energy ◽  
High Speed ◽  
Test System ◽  
Hydraulic Power ◽  
Construction Machinery ◽  
Road Pavement ◽  
Hydraulic Cylinders ◽  
The Impact ◽  
Test Process

A hydraulic breaker for construction machinery generally used for the destroying and disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the measurement of the impact energy of a hydraulic breaker is very important thing to prove its capability to manufacturers and customers. In this study, the test system for measuring the impact energy of a hydraulic breaker was designed and constructed. The test system was consisted with hydraulic cylinders for mounting a breaker, impact absorbing base and frames, pressure and flow sensors, high speed and accurate data acquisition system diesel engine driven hydraulic power unit. The test process of the developed system was carried by measuring guide for tool energy rating for hydraulic breakers which was developed by the CIMA (Construction Industry Manufacturers Association) USA. The developed test system can be applied to measure the impact energy for various kinds of hydraulic breakers.

scholarly journals Experimental Study on the Impact Resistance of Closed-Cell Aluminum Foam Protective Materials to RC Piers under Lateral Impact

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xiwu Zhou ◽  
Wen Zhang ◽  
Xiangyu Wang ◽  
Wenchao Zhang ◽  
Meng Zhan
Keyword(s):  
Impact Energy ◽  
Aluminum Foam ◽  
Impact Force ◽  
Experimental Testing ◽  
Test System ◽  
Protective Effects ◽  
Lateral Impact ◽  
Cumulative Impact ◽  
Closed Cell ◽  
The Impact

In this study, the lateral impact tests of six RC piers which were protected by closed-cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high-yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.

The impact of traditional plants and their secondary metabolites in the discovery of COVID-19 treatment

2020 ◽  
Vol 26 ◽  
Author(s):  
Shabana Bibi ◽  
Ayesha Sarfraz ◽  
Ghazala Mustafa ◽  
Zeeshan Ahmed ◽  
Muhammad Aurang Zeb ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Test System ◽  
Chemical Information ◽  
System Type ◽  
The Family ◽  
Comprehensive Search ◽  
Coronavirus Infection ◽  
The Impact ◽  
First Time ◽  
Plant Sources

Background: Coronavirus Disease-2019 belongs to the family of viruses which cause a serious pneumonia along with fever, breathing issues and infection of lungs for the first time in China and later spread worldwide. Objective: Several studies and clinical trials have been conducted to identify potential drugs and vaccines for Coronavirus Disease-2019. The present study listed natural secondary metabolites identified from plant sources with antiviral properties and could be safer and tolerable treatment for Coronavirus Disease-2019. Methods: A comprehensive search on the reported studies was conducted using different search engine such as Google scholar, SciFinder, Sciencedirect, Medline PubMed, and Scopus for the collection of research articles based on plantderived secondary metabolites, herbal extracts, and traditional medicine for coronavirus infections. Results: Status of COVID-19 worldwide and information of important molecular targets involved in COVID-19 is described and through literature search, is highlighted that numerous plant species and their extracts possess antiviral properties and studied with respect to Coronavirus treatments. Chemical information, plant source, test system type with mechanism of action for each secondary metabolite is also mentioned in this review paper. Conclusion: The present review has listed plants that have presented antiviral potential in the previous coronavirus pandemics and their secondary metabolites which could be significant for the development of novel and a safer drug which could prevent and cure coronavirus infection worldwide.

Response and failure modes of biaxial warp-knitted flexible composite subject to low-velocity impact

2021 ◽  
pp. 152808372110154
Author(s):  
Ziyu Zhao ◽  
Tianming Liu ◽  
Pibo Ma
Keyword(s):  
Impact Energy ◽  
Linear Density ◽  
Failure Modes ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Minor Effect ◽  
Low Velocity ◽  
Velocity Impact ◽  
Flexible Composites ◽  
The Impact

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.

scholarly journals Impact resistance of steel materials to ballistic ejecta and shelter development using steel deck plates

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroyuki Yamada ◽  
Kohei Tateyama ◽  
Shino Naruke ◽  
Hisashi Sasaki ◽  
Shinichi Torigata ◽  
...  
Keyword(s):  
Impact Energy ◽  
Impact Test ◽  
Impact Resistance ◽  
Protective Layer ◽  
High Strength ◽  
Steel Plates ◽  
Corrugated Plates ◽  
Shelter Construction ◽  
The Impact ◽  
Ballistic Ejecta

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

The Investigation in the Influence of Hardness to Transition Point after Tempering for Boric Carbon Steels

2013 ◽  
Vol 690-693 ◽  
pp. 186-192
Author(s):  
Ho Hua Chung ◽  
Tsong Hsin Chen
Keyword(s):  
Impact Energy ◽  
Carbon Steels ◽  
Material Strength ◽  
Tempering Temperature ◽  
Material Test ◽  
Wire Material ◽  
Steel Material ◽  
The Wire ◽  
The Impact ◽  
Test Fragment

This study concerned the influence of the material strength, ductility and impact energy and the relationship of the broken section profile vs. ductile transition brittle where the steel material was treated under different tempering temperature and hardness. Generally after the steel materials, 10B35 coil wire materials which was generally applied to form screws, was treated by quenching and tempering, its hardness ranged from HRC30 to HRC45. The results showed that the elongation rate beyond 20.4% would be proportional to the impact energy with linear relation, but with reverse proportion to the hardness value. The brittle-tough point of the hardness was set around HRC37 after heat treatment in order to balance the strength and the toughness. In addition, the coil wire materials were analyzed from broken section materials showing good toughness; this represented that the area of the cross section radiation layer due to ductile fracture would largely increase. On the contrary, the wire material test fragment with bad toughness represented that the area of the shear layer due to brittle fracture would largely increase as well. As to that material, if its hardness was greater than or equal to HRC37, that material would have an excellent turning danger from transition. At the same time, when the tempering temperature of the wire steel material was set under 4600C and its corresponding central hardness was about HRC37, the distance between two cementite phase layers suddenly increased. This result leaded to the reason why the wire material test fragment was turned into brittleness from ductility. Therefore, when the fastener was manufactured under tempering treatment, avoiding the tempering brittleness temperature range was necessary.

scholarly journals Application and Development of an Environmentally Friendly Blast Hole Plug for Underground Coal Mines

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Donghui Yang ◽  
Yixin Zhao ◽  
Zhangxuan Ning ◽  
Zhaoheng Lv ◽  
Huafeng Luo
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Low Cost ◽  
Blast Hole ◽  
Environmentally Friendly ◽  
Test System ◽  
Industrial Test ◽  
Labor Intensity ◽  
Rock Blasting ◽  
Hopkinson Pressure Bar ◽  
The Impact

Drilling and blasting technology is one of the main methods for pressure relief in deep mining. The traditional method for blasting hole blockage with clay stemming has many problems, which include a large volume of transportation, excess loading time, and high labor intensity. An environmentally friendly blast hole plug was designed and developed. This method is cheap, closely blocks the hole, is quickly loaded, and is convenient for transportation. The impact test on the plug was carried out using an improved split Hopkinson pressure bar test system, and the industrial test was carried out in underground tunnel of coal mine. The tests results showed that, compared with clay stemming, the new method proposed in this paper could prolong the action time of the detonation gas, prevent premature detonation gas emissions, reduce the unit consumption of explosives, improve the utilization ratio, reduce the labor intensity of workers, and improve the effect of rock blasting with low cost of rock breaking.

Sensitivity Based Approach for Transmission Congestion Management Utilizing Bids for Generation Rescheduling and Load Curtailment

2006 ◽  
Vol 7 (4) ◽  
Author(s):  
Himanshu Kumar Singh ◽  
S.C. Srivastava ◽  
Ashwani Kumar Sharma
Keyword(s):  
Electricity Markets ◽  
Power Flow ◽  
Reactive Power ◽  
Congestion Management ◽  
Test System ◽  
Hyperbolic Function ◽  
Flow Sensitivity ◽  
Fair Competition ◽  
Load Curtailment ◽  
The Impact

One of the most important tasks of System Operator (SO) is to manage congestion as it threatens system security and may cause rise in electricity price resulting in market inefficiency. In corrective action congestion management schemes, it is crucial for SO to select the most sensitive generators to re-schedule their real and reactive powers and the loads to curtail in extreme congestion management. This paper proposed the selection of most sensitive generators and loads to re-schedule their generation and load curtailment based on the improved line flow sensitivity indices to manage congestion. The impact of slack bus on power flow sensitivity factors has been determined to encourage fair competition in the electricity markets. Effect of bilateral and multilateral transactions, and impact of multi-line congestion on congestion cost has also been studied. The generators’ reactive power bid has been modeled by a continuous differentiable tangent hyperbolic function. The proposed concept of congestion management has been tested on a practical 75-bus Indian system and IEEE-118-bus test system.

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