Wind-missile impact capacity of essential facilities

2007 ◽  
Vol 5 (2) ◽  
pp. 27
Author(s):  
Nur Yazdani, PhD ◽  
Perry Green, PhD ◽  
Saif Haroon, PhD
Keyword(s):  
Literature Review ◽  
Impact Test ◽  
Building Codes ◽  
Impact Testing ◽  
Economic Losses ◽  
Concrete Panels ◽  
Building Facades ◽  
Large Wind ◽  
Wall Components ◽  
Basic Test

Windborne debris during a hurricane may cause damage to building façades, resulting in significant economic losses and injury or death. Recent building codes have adopted variations of the large-wind-missile impact test in order to certify roof/wall components for hurricane resistance. The purpose of this study was to investigate the performance of commonly used Florida wall and roof assemblies under enhanced large-wind-missile impact testing, beyond the basic test specified in the Florida Building Code. Relevant standards specify similar enhanced standards for essential facilities and shelters. Based on a thorough literature review, a list of wall and roof assemblies that had not been tested before was selected. Wall assemblies included wood and metal framing systems and concrete panels. Roof assemblies included metal framing systems and concrete panels. A comprehensive list of wall and roof assemblies that passed the enhanced test was developed. Assemblies that should be avoided in the construction of essential facilities were also noted.

Effect of Hydrogen Content on Impact Property of A357 Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1201-1204 ◽  
Author(s):  
Yang Li ◽  
Zheng Bing Xu ◽  
Jian Min Zeng
Keyword(s):  
Crack Propagation ◽  
Hydrogen Content ◽  
Impact Test ◽  
Testing Machine ◽  
Initial Crack ◽  
Impact Testing ◽  
Total Absorption ◽  
A357 Alloy ◽  
Absorption Energy ◽  
The Impact

The impact specimens with different hydrogen contents were solution treated at 540±3°C for 12h; water quenched at 60-100°C; and aged at 165±1°C for 6h. The impact test was carried out at Roell450 pendulum impact testing machine. The impact test results show that the impact energy has strong relation with the hydrogen content. The total absorption energy increases with the increasing of hydrogen content. The crack propagation energy Avp and present larger proportion than the initial crack energy Avi in the total absorption energy Av. The number of the pinholes increases and the pinholes turn from smaller irregular ones into sub-circular shape ones. The specimen with irregular sub-circular pinholes has larger KI, and has more crack propagation resistance.

Modeling of Sleeved Taylor Impact Specimens

2003 ◽  
Author(s):  
William Keith Rule
Keyword(s):  
Stress State ◽  
Impact Test ◽  
Sliding Friction ◽  
Experimental Studies ◽  
Impact Testing ◽  
Strength Model ◽  
The Core ◽  
Post Test ◽  
Taylor Impact ◽  
Sliding Friction Coefficient

Recently experimental studies have been conducted using a novel form of the Taylor impact test consisting of sleeved cylinders. A soft material of known properties (OFHC Cu) was used for the core and the tight fitting sleeve was fabricated from the material of interest (AF1410 steel). On impact the mushrooming and sliding core places the sleeve in a stress state not normally found in Taylor impact testing. This paper describes a study conducted to evaluate the feasibility of backing out Johnson-Cook strength model coefficients from measured (post-test) deformed geometries of sleeved specimens using an explicit impact code (EPIC). In addition, modifications to the sleeved concept geometry (tapered and capped core) are also explored numerically as well as the sleeve/core sliding friction coefficient.

scholarly journals Comparison of Lifetime of the PVD Coatings in Laboratory Dynamic Impact Test and Industrial Fine Blanking Process

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2154
Author(s):  
Josef Daniel ◽  
Radek Žemlička ◽  
Jan Grossman ◽  
Andreas Lümkemann ◽  
Peter Tapp ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Testing ◽  
Pvd Coatings ◽  
Dynamic Impact ◽  
Repeated Impact ◽  
Suitable Alternative ◽  
Fine Blanking ◽  
Blanking Process

Protective hard PVD coatings are used to improve the endurance of the tools exposed to repeated impact load, e.g., fine blanking punches. During the fine blanking process, a coated punch repeatedly impacts sheet metal. Thus, the coating which protects the punch surface is exposed to the dynamic impact load. On the other hand, the laboratory method of dynamic impact testing is well known and used for the development and optimization of protective coatings. This paper is focused on the comparison of tool life and lifetime of the industrial prepared PVD coatings exposed to repeated dynamic impact load in the industrial fine blanking process and the laboratory dynamic impact testing. Three different types of protective coatings were tested and the results were discussed. It was shown that the lifetime of coated specimens in both the fine blanking and the dynamic impact processes was influenced by similar mechanical properties of the protective coatings. The qualitative comparison shows that the lifetime obtained by the dynamic impact test was the same as the lifetime obtained by the industrial fine blanking process. The laboratory impact test appears to be a suitable alternative for the optimisation and development of protective PVD coatings for punches used in the industrial fine blanking process.

Operational Modal Analysis of Aluminum Beams

2007 ◽  
Vol 50 (1) ◽  
pp. 74-85 ◽  
Author(s):  
S. Rudroju ◽  
A. Gupta ◽  
S. Yandamuri
Keyword(s):  
Modal Analysis ◽  
Impact Test ◽  
Force Measurement ◽  
Operating Conditions ◽  
Impact Testing ◽  
Operational Modal Analysis ◽  
Normal Functioning ◽  
Large Structures ◽  
Output Only ◽  
Ambient Excitation

Natural frequencies obtained by modal analysis are important to engineers interested in predicting the dynamic behavior of structures. Traditional modal analysis involves impact testing or shaker testing, where response signal and input force are measured to obtain the transfer function. However, for large structures, input excitation force measurement may be difficult, if not impossible. Large structures may be subjected to ambient excitation; operational modal analysis (OMA), also known as output-only modal analysis, has been used for extracting modal parameters of these types of structures. The main advantage of operational modal analysis is that no artificial excitation is needed, and the analysis is based on measurements of only the output data of the system. Operational modal analysis tests are performed under the actual operating conditions of the system without any change of boundary conditions; the tests use the ambient loads as input and thus do not interfere with the normal functioning of the system. In this study, six aluminum beams of different configurations (beams with and without cuts of various lengths) were used for conducting experiments. Results based on impact test, shaker test, and operational modal analysis are presented.

scholarly journals A literature review: The comparison of the sedimentation and flotation technique for Fasciola hepatica detection in livestok

2021 ◽  
Vol 2 (2) ◽  
pp. 79-85
Author(s):  
Alisa Qudrotun Munawaroh ◽  
Endry Nugroho Prasetyo ◽  
Maharani Pertiwi Koentjoro
Keyword(s):  
Literature Review ◽  
Recovery Rate ◽  
Fasciola Hepatica ◽  
Fasciola Gigantica ◽  
Economic Losses ◽  
Nacl Solution ◽  
Combined Method ◽  
Fasciola Species ◽  
Observation Methods ◽  
Flotation Technique

Fascioliasis is an infection of the trematodes of Fasciola hepatica and Fasciola gigantica which causes disease worldwide. This trematode infection commonly attacks ruminants, especially in cattle, buffalo, sheep, goats, pigs and humans, as well. This disease can cause significant economic losses in the livestock industry, mainly through death, liver damage, reduced production of meat, milk and wool, and expenses for deworming. Parasitological examination for identification of fasciola infection was carried out by visually observing fecal samples for adult worms and then examined by simple flotation (using saturated NaCl solution) and formalin-ethyl acetate sedimentation techniques. Here, we were systematically reviewed existing knowledge about sensitive and efficient fasciola observation methods for the identification of fasciola species. Four databases of articles that met the inclusion requirements were compiled for the literature review. This article was published between 2015-2020 and reports on the identification of fasciola species using one or a combination of sedimentation and flotation methods. As a result, the combined method of sedimentation and flotation has the best sensitivity and egg recovery rate (Ef) values for fasciola identification.   Abstrak Fascioliasis merupakan infeksi trematoda spesies Fasciola hepatica dan Fasciola gigantica yang menimbulkan penyakit di seluruh dunia. Infeksi trematoda ini umum menyerang ruminansia, terutama pada sapi, kerbau, domba, kambing, babi dan bisa terjadi pada manusia. Penyakit ini dapat menimbulkan kerugian ekonomi yang cukup besar dalam industri ternak, terutama melalui kematian, kerusakan hati, berkurangnya produksi daging, susu, dan wol, dan pengeluaran biaya untuk obat cacing. Pemeriksaan parasitologi untuk identifikasi infeksi fasciola dilakukan dengan mengamati sampel feses secara visual untuk cacing dewasa dan kemudian diperiksa dengan cara flotasi sederhana (menggunakan larutan NaCl jenuh) dan teknik sedimentasi formalin-etil asetat. Disini, kami meninjau secara sistematis pengetahuan yang ada tentang metode pengamatan fasciola yang sensitif dan efisien dalam identifikasi spesies fascioal. Empat data base artikel yang telah memenuhi syarat inklusi disusun untuk tinjauan literature review. Artikel ini terbit antara tahun 2015-2020 dan melaporkan identifikasi spesies fasciola menggunakan salah satu atau gabungan metode sedimentasi dan flotasi. Hasilnya, metode gabungan antara sedimentasi dan flotasi memiliki nilai sensitivitas dan nilai tingkat pemulihan telur (egg recovery rate, Ef) paling baik untuk identifikasi fasciola.

scholarly journals Environmental and Management Factors Affecting Carrot Cracking

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 852B-852
Author(s):  
T.K. Hartz* ◽  
P.R. Johnstone ◽  
J.J. Nunez
Keyword(s):  
Air Temperature ◽  
Impact Test ◽  
Irrigation Management ◽  
Nutrient Status ◽  
N Fertilization ◽  
Impact Testing ◽  
Dominant Factor ◽  
Factors Affecting ◽  
The Impact ◽  
Cracking Sensitivity

Cracking of carrot (Daucus carota L.) roots during harvest and handling is a serious problem for the commercial industry, particularly for `cut and peeled' products. Thirty commercial fields of cv. `Sugar Snax' in California were surveyed over the period 2000-03. Soil texture was determined, and soil and crop nutrient status, air temperature and soil moisture were monitored. In 10 fields the effect of excessive N fertilization was investigated; 90-180 kg·ha-1 N was sidedressed in addition to the growers' N regime. At one site a comparison of 10 cultivars was conducted to determine the root cracking sensitivity of commercial cultivars suitable for the cut and peeled market. In all fields roots were hand harvested, with undamaged roots 18-24 mm in diameter selected for study. Roots were cooled to 5 °C and subjected to an impact test to rate cracking sensitivity. Fields varied widely in root cracking sensitivity, with 4% to76% of roots cracked in the impact test. Cracking sensitivity was positively correlated with the % silt and clay in soil, and with air temperature in the final month of growth. Irrigation management had no consistent effect on cracking sensitivity. N application in excess of the growers' N regime did not increase carrot yield, but increased root cracking sensitivity by an average of 30%. Root cracking varied among cultivars from 10% to 49%. However, when the periderm was peeled from roots before impact testing, incidence of cracking declined to 2% or less in all cultivars. Periderm strength or flexibility is apparently the dominant factor in carrot cracking sensitivity, and environmental and management variables that affect cracking sensitivity must do so by affecting the periderm structure.

scholarly journals A literature review on Building Integrated Solar Energy Systems (BI-SES) for façades − photovoltaic, thermal and hybrid systems

2022 ◽  
Vol 7 ◽  
pp. 7
Author(s):  
Karol Bot ◽  
Laura Aelenei ◽  
Maria da Glória Gomes ◽  
Carlos Santos Silva
Keyword(s):  
Systematic Review ◽  
Solar Energy ◽  
Literature Review ◽  
Parametric Analysis ◽  
Energy Systems ◽  
Experimental Simulation ◽  
Simulation Tool ◽  
Strategic Development ◽  
Building Facades ◽  
And Performance

The building façade has a crucial role in acting as the interface between the environment and the indoor ambient, and from an engineering and architecture perspective, in the last years, there has been a growing focus on the strategic development of building façades. In this sense, this work aims to present a literature review for the Building Integrated Solar Energy Systems (BI-SES) for façades, subdivided into three categories: thermal, photovoltaic and hybrid (both thermal and photovoltaic). The methodology used corresponds to a systematic review method. A sample of 75 works was reviewed (16 works on thermal BI-SES, 37 works on photovoltaic BI-SES, 22 works on hybrid BI-SES). This article summarises the works and later classifies them according to the type of study (numerical or experimental), simulation tool, parametric analysis and performance when applied.

scholarly journals Investigation on the Application of Taylor Impact Test to High-G Loading

2021 ◽  
Vol 8 ◽  
Author(s):  
Li Juncheng ◽  
Chen Gang ◽  
Lu Yonggang ◽  
Huang Fenglei
Keyword(s):  
Pulse Duration ◽  
Impact Loading ◽  
Impact Test ◽  
Impact Load ◽  
Low Cost ◽  
Large Mass ◽  
Impact Testing ◽  
Taylor Impact ◽  
Taylor Impact Test ◽  
The Impact

Taylor impact test is characterized by high impact energy, low cost, and good repeatability, giving it the technical foundation and development potential for application in high-g loading. In this paper, the feasibility of performing high-g load impact testing to a missile-borne recorder by conducting Taylor impact test was studied by combining simulation analyses with experimental verification. Acccording to the actual dimensions of the missile-borne recorder, an experimental piece was designed based on the Taylor impact principle. The impact loading characteristics of the missile-borne recorder were then simulated and analyzed at different impact velocities. In addition, the peak acceleration function and the pulse duration function of the load were fitted to guide the experimental design. A Taylor-Hopkinson impact experiment was also conducted to measure the impact load that was actually experienced by the missile-borne recorder and the results were compared with the results of strain measurements on the Hopkinson incident bar. The results showed that the peak value of impact load, the pulse duration and the waveform of the actual experimental results were in good agreement with the results predicted by the simulations. Additionally, the strain data measured on the incident bar could be used to verify or replace the acceleration testing of the specimen to simplify the experimental process required. Based on the impact velocity, high-g loading impact was achieved with peak values in the 7,000–30,000 g range and durations of 1.3–1 ms, and the waveform generated was a sawtooth wave. The research results provide a new approach for high amplitude and long pulse duration impact loading to large-mass components, and broaden the application field of Taylor impact test.

scholarly journals Impact, Hardness and Fracture Morphology of Aluminium Alloy (Al-Si) filled Cobalt Oxide Nanoparticles at Various Stir Casting Temperatures

2021 ◽  
Vol 5 (1) ◽  
pp. 11-20
Author(s):  
Mardy Suhandani ◽  
Poppy Puspitasari ◽  
Jeefferie Abd Razak
Keyword(s):  
Impact Toughness ◽  
Melting Temperature ◽  
Impact Test ◽  
Casting Process ◽  
Fracture Morphology ◽  
Stir Casting ◽  
Impact Testing ◽  
Test Results ◽  
The Impact ◽  
Coo Nanoparticles

The automotive and aviation fields require engineering materials that can save and optimise fuel consumption. Unique characteristics of lightweight, higher strength to weight ratio, good corrosion resistance, and good castability are indispensable for castable metal such as Silicon Aluminium (Al-Si). The mechanical properties of Al-Si could be further improved through the addition of Cobalt Oxide (CoO) nanoparticles during the casting process. The importance and purpose of this study were to determine the impact toughness, hardness and fracture morphology of Al-Si metal alloy filled with 0.015 wt.% CoO nanofiller at the various melting temperature of 750 °C, 800 °C and 850 °C. The stir casting method was utilised considering the most appropriate method for mixing nanoparticles powder into the Al-Si matrix. Three test specimens were prepared for each temperature variation. Impact testing using the Charpy method (ASTM E23-56 T) and hardness testing using Rockwell Superficial HR15T and fracture morphology obtained from impact testing fractures were performed accordingly. The impact test results showed that the Al-Si added with 0.015% CoO at 800 °C of melting temperature possessed the highest impact toughness value of 25.111 x 10-3 Joule mm-2 than the other variations. The hardness test results showed that Al-Si added 0.015% CoO with a melting temperature of 850 °C had the highest hardness value of 79.52 HR15T. The fracture morphology of the impact test in all specimens shows uniform brittle fracture characteristics. It is found that the melting temperature during the stir-casting process of Al-Si has played a significant role in influencing the resulted properties of Al-Si filled CoO nanoparticles metal matrix composites. The selection of an accurate melting temperature for the stir casting process will affect the resulted properties of produced metal composites.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

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