Experimental Data on Seismic Response of Piping Components

1998 ◽  
Vol 120 (4) ◽  
pp. 449-455 ◽  
Author(s):  
G. C. Slagis
Keyword(s):  
Experimental Data ◽  
Seismic Performance ◽  
Low Frequency ◽  
Time History ◽  
High Amplitude ◽  
Dynamic Reliability ◽  
Performance Trends ◽  
Potential Failure ◽  
High Level ◽  
The Impact

Experimental data from the EPRI Piping and Fitting Dynamic Reliability Program are evaluated. High-amplitude, seismic time history loads were applied to 32 piping components in a cantilevered configuration. Components included elbows, tees, reducers, a reinforced fabricated tee, a nozzle, and lugs. The test levels were about 2 to 8 times Level D. The seismic capability of elbows is shown to be remarkable. The seismic performance of lugs is judged to be poor. The tests demonstrate that collapse is a potential failure mode, particularly in low-frequency systems. The tests also demonstrate that a fatigue failure in a single, high-level, seismic event is possible. Of the 15 nonelbow tests that failed by fatigue, six (40 percent) failed during the first high-level seismic test. Design and fabrication details are crucial to seismic performance. Trends in the data need to be assessed to determine appropriate Section III stress limits for seismic loads. In particular, the impact of component frequency on seismic capability has to be quantified.

A dynamic source model for the San Fernando earthquake

1978 ◽  
Vol 68 (6) ◽  
pp. 1555-1576
Author(s):  
Michel Bouchon
Keyword(s):  
Fault Plane ◽  
High Stress ◽  
Time History ◽  
High Strength ◽  
High Amplitude ◽  
Tectonic Stress ◽  
Source Model ◽  
Dynamic Crack ◽  
San Fernando ◽  
High Level

abstract We model the San Fernando earthquake as a propagating rupture in a half-space, using for the slip-time-history on the fault plane analytical expressions which approximate the slip functions of dynamic crack models obtained by Das and Aki (1977a, b). We synthesize the strong ground motions and accelerations at the Pacoima Dam site and compute the teleseismic signals for different models of cracks. Three major featuras of the data–the strong pulse associated with the beginning of the rupture, the high acceleration phase on the Pacoima Dam records, and the presence of ripples on the teleseismic seismograms–which are not compatible with a smooth rupture process, are well explained by a crack with barriers model where the rupture encounters, along the fault plane, barriers or obstacles of high strength materials which may remain unbroken after the passage of the rupture front. A high-stress drop (400 to 500 bars) is required in the hypocentral area to explain the high-amplitude short-duration first pulse of the teleseismic records. This indicates a high level of tectonic stress in the area. A study of the earthquake series following the main shock shows that the aftershocks which took place in the region where major slipping occurred during the earthquake may represent the release of some of the barriers.

Low Frequency Noise Analysis in Advanced CMOS Devices

2011 ◽  
Vol 324 ◽  
pp. 441-444 ◽  
Author(s):  
Jalal Jomaah ◽  
Majida Fadlallah ◽  
Gerard Ghibaudo
Keyword(s):  
Experimental Data ◽  
Noise Analysis ◽  
Low Frequency ◽  
Deep Submicron ◽  
Electrical Noise ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Noise Sources ◽  
The Impact ◽  
Mobility Fluctuations

A review of recent results concerning the low frequency noise in modern CMOS devices is given. The approaches such as the carrier number and the Hooge mobility fluctuations used for the analysis of the noise sources are illustrated through experimental data obtained on advanced CMOS generations. Furthermore, the impact on the electrical noise of the shrinking of CMOS devices in the deep submicron range is also shown.

Study on the Uplift Force of Plunge Pool Slab

2014 ◽  
Vol 580-583 ◽  
pp. 1897-1900
Author(s):  
Chun Tao Wang ◽  
Bang Hua Xie ◽  
Wen Hui Zeng
Keyword(s):  
Low Frequency ◽  
Time History ◽  
Uplift Force ◽  
Plunge Pool ◽  
Discharge Water ◽  
Amplitude Vibration ◽  
History Of ◽  
Force Time ◽  
The Impact ◽  
Test Result

The impact of the flood discharge water flow from a high dam is rather great on the slab of a plunge pool, and may cause damages to the plunge pool and consequently endangers the dam body safety. Therefore, a reverse arch slab model was established on the base of a study on and a simulation of the rational scale of gaps between the plates of the plunge pool slab. The model was an arch ring containing 7 slabs. The uplift force time history of each slab was measured, and the uplift force power spectrum and probability density were analyzed. The test result shows that the uplift energy mainly centers in 0-15Hz frequency bandwidth, and mostly within 1Hz. It belongs to a low frequency and big amplitude vibration.

A Hierarchical Impact Force Reconstruction Method for Aerospace Composites

2019 ◽  
Vol 812 ◽  
pp. 17-24
Author(s):  
Mario Emanuele de Simone ◽  
Francesco Ciampa ◽  
Michele Meo
Keyword(s):  
Impact Force ◽  
Research Work ◽  
Time History ◽  
Low Velocity Impact ◽  
Reconstruction Method ◽  
Low Velocity ◽  
Force Reconstruction ◽  
Structural Responses ◽  
High Level ◽  
The Impact

This research work presents a hierarchical method able to reconstruct the time history of the impact force on a composite wing stringer-skin panel by using the structural responses measured by a set of surface bonded ultrasonic transducers. Time reversal method was used to identify the impact location by the knowledge of structural responses recorded from a set of excitation points arbitrarily chosen on the plane of the structure. Radial basis function interpolation approach was then used to calculate the transfer function at the impact point and reconstruct the impact force history. Experimental results showed the high level of accuracy of the proposed impact force reconstruction method for a number of low-velocity impact sources and energies.

Study on the Method of Structural Seismic Performance Evaluation Based on the Damage Spectra

2010 ◽  
Vol 163-167 ◽  
pp. 4324-4330
Author(s):  
Jun Teng ◽  
Hu Bing Tu
Keyword(s):  
Performance Evaluation ◽  
Seismic Performance ◽  
Structural Damage ◽  
Evaluation Method ◽  
Low Cycle Fatigue ◽  
Time History ◽  
Seismic Damage ◽  
Hysteretic Energy ◽  
Seismic Performance Evaluation ◽  
The Impact

Park-Ang seismic damage model is increasingly concerned due to it considers not only maximum elasto-plastic deformation, but also low cycle fatigue accumulated hysteretic energy, while research on the method of seismic performance evaluation based on the model is still rare. Therefore, a new evaluation method on the basis of damage spectra is proposed in this paper. Damage spectra of site I considering three kinds of ultimate deformation ductility factor are built firstly, and then transformation relationship between damage of MDOF and SDOF of frame structures is researched. Lastly, procedure of seismic damage evaluation on the structure is proposed. An example is used to confirm the validity of the spectra-based seismic performance evaluation method. The example analysis shows that: the method proposed here is reasonable to consider the impact of the cumulative hysteretic energy on the structural damage. The results from the method have good consistency with the time history analysis results. It can assess the extent of structural damage from the statistical viewpoint.

scholarly journals Analysis on the Influence of Increasing Seismic Fortification Intensity on Seismic Performance of Underground Station

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Ying Zeng ◽  
Shiguang Xu ◽  
Shiqian Yin
Keyword(s):  
Ground Motion ◽  
Seismic Performance ◽  
Time History ◽  
Time History Analysis ◽  
Structural Deformation ◽  
Equivalent Linearization ◽  
History Analysis ◽  
Underground Station ◽  
The Impact ◽  
Station Structure

China Earthquake Parameter Zoning (2016) has increased the seismic fortification intensity in Chengdu from VII to VIII. It is necessary to conduct in-depth discussion on the impact of the seismic performance of the built underground station structure. In this paper, a stratum-structure finite element model is established with a Chengdu subway station as an example. The model boundary adopts viscoelastic boundary, and the ground motion is input in the form of equivalent nodal force. The equivalent linearization method is used to consider the nonlinearity of soil materials. The time-history analysis of seismic fortification intensity of VII and VIII degrees is carried out, respectively. By comparing the calculation results of the two seismic fortification intensity ground motion conditions, it is concluded that the connection between the side wall and the floor is the weakest position of the station structure under the action of the earthquake; the seismic fortification intensity is increased from VII to VIII to the internal force of the structure. It has a relatively large impact, especially the most obvious impact on the bending moment. The results of the verification of the seismic time-history analysis show that the increase of fortification intensity will have a more obvious impact on the structural deformation, and the structural design of the station can meet the safety performance requirements of VII and VIII degrees of seismic fortification. The research has certain reference significance for the seismic safety evaluation of the built underground station structure in Chengdu area.

scholarly journals Seismic performance comparison between force-based and performance-based design as per Canadian Highway Bridge Design Code (CHBDC) 2014

2016 ◽  
Vol 43 (8) ◽  
pp. 741-748 ◽  
Author(s):  
Qi Zhang ◽  
M. Shahria Alam ◽  
Saqib Khan ◽  
Jianping Jiang
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Performance Based Design ◽  
Performance Criteria ◽  
Highway Bridge ◽  
Reinforcing Steel ◽  
Earthquake Hazards ◽  
Design Code ◽  
Bridge Design ◽  
The Impact

Performance-based design (PBD) was first introduced in Canadian Highway Bridge Design Code (CHBDC) in 2014. Performance-based design is the design that meets multiple performance criteria under different earthquake hazards. To investigate the impact of changes in CHBDC 2014, a four-span concrete highway bridge is designed and evaluated using force-based design (FBD) and PBD methods as per CHBDC 2014, and FBD method as per CHBDC 2006. By incorporating soil–structure interaction (using p–y curves) nonlinear pushover and dynamic time history analyses are conducted to assess the seismic performance of these bridges. Maximum strains of concrete and reinforcing steel are compared among the three designs to determine their performance levels. It is concluded that PBD (CHBDC 2014) is highly conservative compared to FBD (for both CHBDC 2014 and 2006). For the three-level PBD approach, the design is governed by the criterion of reinforcing steel not yielding under the design earthquake (with 475 years return period).

scholarly journals Study on Quasi-Static Loading Protocols considering the Action Characteristics of Long-Period Ground Motions

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ke Yang ◽  
Bo Wang ◽  
Jiawei Zhang ◽  
Zhe Li ◽  
Boquan Liu
Keyword(s):  
Seismic Performance ◽  
Static Loading ◽  
Ground Motions ◽  
Low Frequency ◽  
Time History ◽  
Experimental Investigations ◽  
Structural Components ◽  
Cycle Number ◽  
Long Period ◽  
Nonlinear Time History

Due to abundant low-frequency components of long-period ground motions (LPGMs), long-period structures are susceptible to severe damage. The corresponding time-history displacement responses have significant “large-displacement” and “long-duration” characteristics. These action characteristics essentially reflect the different loading paths imposed on structures of LPGMs from ordinary ground motions (OGMs). Hence, revealing the influence mechanism of the action characteristics on the seismic performance of structural components is the key to investigating the influence of LPGMs on the whole structure. This paper presents a kind of quasi-static loading protocol considering the action characteristics of LPGMs. Firstly, nonlinear time-history analyses on structural systems subjected to 50 selected representative LPGMs were conducted. Inelastic cycles and corresponding amplitudes of time-history displacement responses under LPGMs were statistically analyzed through the rainflow method. Then, considering two of the most significant factors, structural period and target ductility, a prediction model of cycle number and cycle amplitude was obtained by regression. On this basis, the quasi-static loading protocol considering the action characteristics of LPGMs was developed. Proposed protocols can be directly applied to experimental investigations on the seismic performance for structural components under LPGMs.

ПРАГМАТИЧНИЙ ПОТЕНЦІАЛ НАТИВНОЇ РЕКЛАМИ: ФОРМИ, ТРЕНДИ (НА ПРИКЛАДІ НАТИВНОГО КОНТЕНТУ В СОЦІАЛЬНІЙ МЕРЕЖІ FACEBOOK ЩОДО БРЕНДА ФАКУЛЬТЕТУ ЖУРНАЛІСТИКИ ЗНУ)

2020 ◽  
pp. 113
Author(s):  
V. Kovpak ◽  
N. Trotsenko
Keyword(s):  
Social Network ◽  
Professional Training ◽  
Educational Process ◽  
Communication Strategy ◽  
Student Centered ◽  
Teacher Student ◽  
The Social ◽  
National University ◽  
High Level ◽  
The Impact

<div><p><em>The article analyzes the peculiarities of the format of native advertising in the media space, its pragmatic potential (in particular, on the example of native content in the social network Facebook by the brand of the journalism department of ZNU), highlights the types and trends of native advertising. The following research methods were used to achieve the purpose of intelligence: descriptive (content content, including various examples), comparative (content presentation options) and typological (types, trends of native advertising, in particular, cross-media as an opportunity to submit content in different formats (video, audio, photos, text, infographics, etc.)), content analysis method using Internet services (using Popsters service). And the native code for analytics was the page of the journalism department of Zaporizhzhya National University on the social network Facebook. After all, the brand of the journalism department of Zaporozhye National University in 2019 celebrates its 15th anniversary. The brand vector is its value component and professional training with balanced distribution of theoretical and practical blocks (seven practices), student-centered (democratic interaction and high-level teacher-student dialogue) and integration into Ukrainian and world educational process (participation in grant programs).</em></p></div><p><em>And advertising on social networks is also a kind of native content, which does not appear in special blocks, and is organically inscribed on one page or another and unobtrusively offers, just remembering the product as if «to the word». Popsters service functionality, which evaluates an account (or linked accounts of one person) for 35 parameters, but the main three areas: reach or influence, or how many users evaluate, comment on the recording; true reach – the number of people affected; network score – an assessment of the audience’s response to the impact, or how far the network information diverges (how many share information on this page).</em></p><p><strong><em>Key words:</em></strong><em> nativeness, native advertising, branded content, special project, communication strategy.</em></p>

THE IMPACT OF UKRAINE'S EXCISE DUTY POLICY ON THE TRANSFORMATION PROCESSES OF THE TOBACCO MARKET

2020 ◽  
Vol 2020 (10) ◽  
pp. 19-33
Author(s):  
Nadiia NOVYTSKA ◽  
◽  
Inna KHLIEBNIKOVA ◽  
Keyword(s):  
Structural Changes ◽  
Tax Avoidance ◽  
Transformation Process ◽  
State Regulation ◽  
Tobacco Products ◽  
Excise Duty ◽  
Increasing Demand ◽  
High Level ◽  
The Impact ◽  
Transformation Processes

The market of tobacco products in Ukraine is one of the most dynamic and competitive. It develops under the influence of certain factors that cause structural changes, therefore, the aim of the article is to conduct a comprehensive analysis of transformation processes in the market of tobacco and their alternatives in Ukraine and identify the factors that cause them. The high level of tax burden and the proliferation of alternative products with a potentially lower risk to human health, including heating tobacco products and e-cigarettes, are key factors in the market’s transformation process. Their presence leads to an increase in illicit turnover of tobacco products, which accounts for 6.37% of the market, and the gradual replacement of cigarettes with alternative products, which account for 12.95%. The presence on the market of products that are not taxed or taxed at lower rates is one of the reasons for the reduction of excise duty revenues. According to the results of 2019, the planned indicators of revenues were not met by 23.5%. Other reasons for non-fulfillment of excise duty revenues include: declining dynamics of the tobacco products market; reduction in the number of smokers; reorientation of «cheap whites» cigarette flows from Ukraine to neighboring countries; tax avoidance. Prospects for further research are identified, namely the need to develop measures for state regulation and optimization of excise duty taxation of tobacco products and their alternatives, taking into account the risks to public health and increasing demand of illegal products.

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