Dynamics Characteristic Analysis of Deliberate Mistuned Bladed-Disk System in Compressor Based on Substructure Method

2011 ◽  
Vol 141 ◽  
pp. 129-133 ◽  
Author(s):  
Hui Qun Yuan ◽  
Liang Zhang ◽  
Lin Song
Keyword(s):  
Elastic Modulus ◽  
Dynamic Test ◽  
Frequency Difference ◽  
Test Results ◽  
Characteristic Analysis ◽  
Disk System ◽  
Substructure Method ◽  
Bladed Disk ◽  
Dynamics Characteristic ◽  
Large Frequency

In this paper, based on the test data of blade static frequency and simulating blade deliberate mistuned by changing elastic modulus, a method combining dichotomy and finite element is presented which can identify elastic modulus parameters of mistuned blades. Then, when value of the frequency difference is 5Hz and 41Hz, dynamic characteristics of deliberate mistuned bladed-disk system are investigated separately under operating speed, on the basis of substructure method. Apply the exciting force of airflow on the fronts of blades tip. According to dynamic test results, it takes 4 as the excitation order. The analysis results show that with the mistuned frequency difference increasing, the largest amplitude of blade will decrease gradually. The deliberate mistuned scheme of large frequency difference as scheme Ⅱ is more effective than the small one as schemeⅠto reduce the vibration of bladed disk system under working speed of 11300r/min. The analysis results are consistent with the dynamic test ones.

Dynamics Characteristic Analysis of Deliberate Mistuned Bladed-Disk System in Compressor Based on CMS Mothod

2011 ◽  
Vol 305 ◽  
pp. 192-197 ◽  
Author(s):  
Hui Qun Yuan ◽  
Liang Zhang
Keyword(s):  
Dynamic Test ◽  
Frequency Difference ◽  
Costal Margin ◽  
Test Results ◽  
Characteristic Analysis ◽  
Disk System ◽  
Rotating Speed ◽  
Bladed Disk ◽  
Dynamics Characteristic ◽  
Better Than

In this paper first,a method combining dichotomy and finite element is presented which identify elastic modulus parameters of mistuned bladed based on the test data of blade static frequency and simulation blade deliberate mistuned by change elastic modulus.Then, dynamic characteristics of deliberate mistuned 10Hz and 41Hz bladed-disk system were analyzed in work rotating speed based on CMS mothod, respectively. The exciting force of airflow exert on costal margin of blade tip.According to dynamic test results,the incentive order is 4. The analysis results show that along with the mistuning frequency difference increases,the largest amplitude of blade is becoming smaller(except tuned system) , and scheme of large frequency difference 41Hz deliberate mistuned (scheme Ⅱ) better than scheme of small frequency difference 10Hz deliberate mistuned (scheme Ⅰ) for vibration reduction of bladed-disk system in work rotating speed for 11300r/min. The analysis results are consistent with the dynamic test results.

Design Forces for Drift and Damage Control: A Second Look at the Substitute Structure Approach

1994 ◽  
Vol 10 (2) ◽  
pp. 319-331 ◽  
Author(s):  
John F. Bonacci
Keyword(s):  
Reinforced Concrete ◽  
Damage Control ◽  
Dynamic Test ◽  
Frame Structures ◽  
Rc Frame ◽  
Test Results ◽  
Structure Approach ◽  
Maximum Displacement ◽  
Design Loads ◽  
Rc Frame Structures

This paper explores the development of a method that is useful for design of reinforced concrete (RC) frame structures to resist earthquakes. The substitute structure method, originally proposed in the 1970s, makes an analogy between viscously damped linear and hysteretic response for the purpose of estimating maximum displacement. The evolution of the method is retraced in order to emphasize its unique reliance on experimental results, which are needed to establish rules for assignment of substitute linear properties. Recent dynamic test results are used to extend significantly the calibration of the method, which furnishes design loads on the basis of drift and damage control.

A Dynamic Test of Fully Prestressed Concrete Beams

2011 ◽  
Vol 368-373 ◽  
pp. 2483-2490
Author(s):  
Yao Ting Zhang ◽  
Yi Zheng ◽  
Hong Jian Li
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Theoretical Analysis ◽  
Natural Frequency ◽  
Axial Force ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Dynamic Test ◽  
Modified Formula

A dynamic test of two unbonded fully prestressed concrete beams has been conducted. The results indicate that the natural frequency of beams increases with the prestress force, which is opposite to the analytical arguments for homogeneous and isotropic beams subject to axial force. This paper explains the change in frequencies by discussing the change in the elastic modulus. A modified formula is also proposed, and the experimental data agree well with the theoretical analysis.

Chaotic Dynamics Characteristic Analysis for Matrix Converter

2013 ◽  
Vol 60 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Changliang Xia ◽  
Peng Song ◽  
Tingna Shi ◽  
Yan Yan
Keyword(s):  
Chaotic Dynamics ◽  
Matrix Converter ◽  
Characteristic Analysis ◽  
Dynamics Characteristic

Dynamic Test of Bird Strike on a Flat Plate Made from LY-12 Aluminium

2013 ◽  
Vol 765-767 ◽  
pp. 3158-3161
Author(s):  
Jun Liu ◽  
Zheng Li Zhang
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Dynamic Test ◽  
Time History ◽  
Aircraft Design ◽  
Bird Strike ◽  
Test Results ◽  
Valuable Data ◽  
Good Agreement ◽  
Peak Value

Tests of bird strike have been carried out on plate made from LY-12 Aluminium. The test was down with the projectile impacting the target perpendicularly at velocity of 40m/s, 80m/s, 120m/s respectively. The displacement-time history curves and strain-time history curves of on LY-12 Aluminium plate were measured. The good agreement of the results between two specimens in one group indicated that the results tested in the presnet paper are reliable. The dynamic response of the plate and damage modes of the bird influenced by striking velocity were analyzed. The peak value of the displacement linear enlarged with the increasing of the striking velocity. The test results in the present paper provided valuable data for aircraft design impacted by bird, and also provided abundant test datas for the numerical simulation model applied in bird striking.

scholarly journals Bakteri Endofit Tanaman Jeruk Nipis (Citrus aurantifolia) Penghasil Asam Indol Asetat (AIA)

2020 ◽  
Vol 13 (2) ◽  
pp. 179-191
Author(s):  
Oktira Roka Aji ◽  
Iva Dita Lestari
Keyword(s):  
Acetic Acid ◽  
Endophytic Bacteria ◽  
Indole Acetic Acid ◽  
Biochemical Analysis ◽  
Crop Productivity ◽  
Bacterial Identification ◽  
Test Results ◽  
Bacterial Isolates ◽  
Characteristic Analysis ◽  
Citrus Aurantifolia

AbstrakBakteri endofit hidup dalam suatu tanaman tanpa menyebabkan gangguan bagi tanaman yang berperan penting dalam menstimulasi pertumbuhan tanaman, yaitu dengan memproduksi fitohormon seperti asam absisat, asam indol asetat, dan sitokinin. Penelitian ini bertujuan untuk mengisolasi, menyeleksi, dan mengidentifikasi bakteri endofit yang terdapat pada daun, batang, dan akar tanaman jeruk nipis (Citrus aurantifolia). Isolat bakteri endofit diseleksi berdasarkan kemampuannya dalam menghasilkan asam indol asetat (AIA). Isolat bakteri endofit ditumbuhkan pada media nutrient broth (NB) yang ditambah dengan L-triptofan. Konsentrasi AIA dihitung dengan penambahan reagen salkowski dan diukur menggunakan spektrofotometer pada panjang gelombang 530 nm. Identifikasi bakteri endofit dilakukan dengan analisis uji biokimia. Isolat bakteri endofit yang berhasil diisolasi sebanyak 12 isolat, yaitu 4 isolat dari daun, 4 isolat dari batang, dan 4 isolat dari akar. Hasil pengamatan pada uji AIA menunjukkan bahwa semua isolat bakteri endofit dapat menghasilkan hormon AIA. Isolat yang menghasilkan konsentrasi hormon AIA tertinggi adalah isolat B2 (6,51 ppm). Isolat bakteri yang berhasil diidentifikasi berasal dari genus Enterobacter, Bacillus, Pseudomonas, dan Staphylococcus. Bakteri endofit yang dapat menghasilkan AIA berpotensi dikembangkan sebagai biofertilizer untuk meningkatkan produktivitas tanaman. Abstract Endophytic bacteria live inside plants without causing disruption to plants and play an important role in stimulating plant growth. This study aims to isolate endophytic bacteria from lime plant (Citrus aurantifolia) and characterize its ability to produce indole acetic acid (IAA). Bacterial isolates were grown on media supplemented with L-tryptophan as IAA precursor. The bacterial supernatant was mixed with salkowski reagents and then measured using a spectrophotometer at 530 nm. Bacterial identification was carried out using biochemical characteristic analysis. A total of 12 endophytic bacterial isolates were successfully isolated from leaves, stem and roots of plants. Quantitative test results showed that all isolates can produce IAA. The highest concentration of IAA was produced by B2 (6.51 ppm). Biochemical analysis indicated that the isolates were from the genus Enterobacter, Bacillus, Pseudomonas and Staphylococcus. Endhophytic bacteria that can produce IAA have the potential to be developed as biofertilizers to increase crop productivity.

Comparative Study on the Pseudo-Dynamic Testing of Semi-Rigid Connection of Steel Frames with or without Brace

2011 ◽  
Vol 194-196 ◽  
pp. 2001-2007
Author(s):  
Jia Lv ◽  
Qi Lin Zhang
Keyword(s):  
Dynamic Testing ◽  
Dynamic Test ◽  
Lateral Force ◽  
Steel Frame ◽  
Seismic Loads ◽  
Test Results ◽  
Shearing Force ◽  
Braced Frame ◽  
Rigid Connection ◽  
Steel Braced Frame

The horizontal stiffness of steel frame is relatively weak. So designers introduce brace system into steel frame to increase the horizontal stiffness. In order to guarantee the safety of the structure, we should imitate the performance of the structure under seismic loads. In this paper, the pseudo-dynamic test was conducted on the semi-rigid connection of steel frame and the semi-rigid connection of steel-braced frame. The test results show that the brace can increase the ductility of the structure, decrease the displacement of the top floor, decrease the interlayer displacement, and bear ground floor shearing-force. So the brace greatly impacts the performance of the structure. It has the ability of anti-earthquake and strong resistance ability of lateral force.

Experimental Study of High Temperature Performance of Steel Suspension Bridge Wires

2019 ◽  
Author(s):  
Jumari A. Robinson ◽  
Adrian Brügger ◽  
Raimondo Betti
Keyword(s):  
Elastic Modulus ◽  
High Temperature ◽  
High Strength Steel ◽  
Cold Working ◽  
High Strength ◽  
Suspension Bridge ◽  
Theoretical Models ◽  
Test Results ◽  
Single Wire ◽  
Steel Wires

<p>The performance of suspension bridges exposed to fire hazards is severely under-studied – so much so that no experimental data exists to quantify the safety of a suspension bridge during or after a major fire event. Bridge performance and safety rely on the integrity of the main cable and its constituent high-strength steel wires. Due to the current lack of experimental high temperature data for wires, the theoretical models use properties and coefficients from data for other types of structural steel. No other structural steel undergoes the amount of cold-working that bridge wire does, and plastic strains from cold-working can be relieved at high temperature, drastically weakening the steel. As such, this work determines the elastic modulus, ultimate strength, and general thermo-mechanical profile of the high-strength steel wires in a range of elevated temperature environments. Specifically, these tests are conducted on a bundle of 61-wires (transient), and at the single wire level (steady-state) at a temperature range of approximately 20-700°C. The test results show an alarmingly high reduction in the elastic modulus and ultimate strength with increased temperature. The degradation shown by experiments is higher than predicted by current theoretical models, indicating that use of high-temperature properties of other types of steel is not sufficient. The test results also show scaling agreement between the single wire and the 61-wire bundle, implying that a full material work up at the single- wire level will accurately inform the failure characterization of the full cable.</p>

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