Relationship between applied force and magnetic field in a pseudo-static test of a portal frame

2020 ◽  
pp. 1-18
Author(s):  
Huan Guo ◽  
Sanqing Su ◽  
Wei Wang ◽  
Xiaoping Ma ◽  
Shuchun Yi ◽  
...  
Keyword(s):  
Equivalent Stress ◽  
Steel Structures ◽  
Magnetic Memory ◽  
Magnetic Signal ◽  
Static Test ◽  
Signal Distribution ◽  
Static Testing ◽  
Portal Frame ◽  
Plastic Phase ◽  
Elastic Stage

Metal magnetic memory (MMM) testing is a nondestructive approach for evaluating the stress concentration and early damage of ferromagnetic components. However, research on the MMM testing of large steel structures has been limited. Thus, this study investigates the suitability of MMM technology for monitoring the damage in steel structures exposed to complex stresses. The normal components of magnetic signals Hp(y) on the beams and columns of a portal frame are obtained through pseudo-static testing. The signal increment ΔHp(y) and its absolute value |ΔHp(y)| under different loads are analyzed. The relationship between the equivalent stress and magnetic signal is investigated through numerical simulation. The results show that the ΔHp(y) curves are similar during the elastic stage but change abruptly during the plastic phase. Moreover, the differences in the magnetic signal directions caused by the varying detection directions cannot be ignored. In the elastic stage, with the increase in the load, |ΔHp(y)| curves initially increase and then decrease. The formation of the ΔHp(y) curve is similar to the distribution of the equivalent stress. The mutation of ΔHp(y) can determine whether a specimen is entering the plastic phase, and can warn against structural failure. The magnetic signal distribution qualitatively reflects the stress distribution.

The Feature Extraction Method of Gear Magnetic Memory Signal

2013 ◽  
Vol 819 ◽  
pp. 206-211
Author(s):  
Yong Gang Xu ◽  
Zhi Cong Xie ◽  
Lin Li Cui ◽  
Jing Wang
Keyword(s):  
Gear Tooth ◽  
Low Frequency ◽  
Magnetic Memory ◽  
Magnetic Signal ◽  
Heavy Load ◽  
Low Speed ◽  
Feature Extraction Method ◽  
Test Technology ◽  
Time Scale Decomposition ◽  
Memory Signals

Magnetic memory test technology is a new nondestructive testing technique, which is able to detect of the stress concentration area and potential fault of low speed and heavy load gear. Because the magnetic memory signals are easy to be disturbed by various sources of noises, a new method based on the intrinsic time-scale decomposition (ITD) is proposed to achieve the extraction of magnetic memory signal. Firstly, the magnetic memory signals are decomposed into several proper rotation components (PRC) and a trend component by ITD. Then reconstruct the first four order PRCs to eliminate the low frequency cyclic composition of magnetic memory signal and magnetic noise. Finally, the magnetic signal strengths of each gear tooth root are extracted using cycle average and local statistic method. The results of Experiments show that the method is suitable to pick up effective ingredients of signal to extract signal feature and has important application value in potential fault diagnosis of low speed and heavy load gearbox.

Equivalent stress for steel box girder with corrugated web under bending based on magnetic memory method

2020 ◽  
Vol 62 (3) ◽  
pp. 501-516 ◽  
Author(s):  
Sanqing Su ◽  
Luxi Wei ◽  
Wei Wang ◽  
Yiyi Yang ◽  
Xiaoping Ma ◽  
...  
Keyword(s):  
Equivalent Stress ◽  
Magnetic Memory ◽  
Box Girder ◽  
Steel Box Girder ◽  
Corrugated Web

Quantitative research of defects for pipelines based on metal magnetic memory testing

2020 ◽  
Vol 62 (5) ◽  
pp. 292-299 ◽  
Author(s):  
Wei Zhou ◽  
Jianchun Fan ◽  
Xiangyuan Liu ◽  
Shujie Liu
Keyword(s):  
Quantitative Research ◽  
Three Dimensional ◽  
Magnetic Memory ◽  
Metal Magnetic Memory ◽  
Magnetic Signal ◽  
Destructive Testing ◽  
Gas Industry ◽  
Defect Profile ◽  
Comparison Results ◽  
Dimensional Distribution

Pipelines are widely used in the oil & gas industry but defects seriously affect their safe operation. Therefore, it is necessary to perform non-destructive testing (NDT) to quantify the defects. In this study, a magnetic dipole model was established to characterise the defects and magnetic flux leakage (MFL) of defects was simulated using the finite element method (FEM) to reveal the spatial distribution of the magnetic vector. Magnetic signals were measured using a tunnel magnetoresistance (TMR) sensor array and the results showed that defects with different sizes could be quantified using the metal magnetic memory (MMM) method. Three-dimensional distribution of the magnetic signal and its gradient reflected the defect profile well and the gradient of the magnetic signal was found to reduce the effect of non-uniform magnetisation. Furthermore, experimental results were verified by comparison with the simulation results and the comparison results showed a consistent variation trend. Quantitative analysis was conducted and the characteristic parameters of the gradients could be used to quantify the defects.

scholarly journals GA-BP Neural Network-Based Strain Prediction in Full-Scale Static Testing of Wind Turbine Blades

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1026 ◽  
Author(s):  
Zheng Liu ◽  
Xin Liu ◽  
Kan Wang ◽  
Zhongwei Liang ◽  
José A.F.O. Correia ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Back Propagation ◽  
Health Assessment ◽  
Prediction Method ◽  
Full Scale ◽  
Wind Turbine Blades ◽  
Static Test ◽  
Static Testing ◽  
Input Variables

This paper proposes a strain prediction method for wind turbine blades using genetic algorithm back propagation neural networks (GA-BPNNs) with applied loads, loading positions, and displacement as inputs, and the study can be used to provide more data for the wind turbine blades’ health assessment and life prediction. Among all parameters to be tested in full-scale static testing of wind turbine blades, strain is very important. The correlation between the blade strain and the applied loads, loading position, displacement, etc., is non-linear, and the number of input variables is too much, thus the calculation and prediction of the blade strain are very complex and difficult. Moreover, the number of measuring points on the blade is limited, so the full-scale blade static test cannot usually provide enough data and information for the improvement of the blade design. As a result of these concerns, this paper studies strain prediction methods for full-scale blade static testing by introducing GA-BPNN. The accuracy and usability of the GA-BPNN prediction model was verified by the comparison with BPNN model and the FEA results. The results show that BPNN can be effectively used to predict the strain of unmeasured points of wind turbine blades.

scholarly journals Dual – loop force – displacement mixed control strategy and its application on the quasi – static test

2018 ◽  
Vol 38 (3) ◽  
pp. 296-302
Author(s):  
Cong Zeng ◽  
Bin Wu ◽  
Guoshan Xu ◽  
Zhen Wang ◽  
Tianlin Pan
Keyword(s):  
Control Strategy ◽  
Axial Loading ◽  
Steel Tube ◽  
Control Performance ◽  
Structural Components ◽  
Static Test ◽  
Static Testing ◽  
Mixed Control ◽  
Excellent Control ◽  
Force Displacement

The Quasi-static test is a well-known powerful methodology to evaluate the seismic performance of structural components and systems. One of the most important challenges in the Quasi-static testing is to achieve precise boundary conditions, especially for the axial loading of vertical components. The requirement of synchronized displacement loading and target axial force formed a pair of contradiction. A dual-loop force-displacement mixed control strategy is proposed. The presented approach is successfully verified through the quasi-static testing for a full-scale concrete filled steel tube column. The control targets are achieved with an excellent control performance.

scholarly journals ANALISIS PEMBEBANAN STATIK PADA RANGKA BOGIE AUTOMATIC PEOPLE MOVER SYSTEM (APMS)MENGGUNAKAN STANDAR UIC-615 DENGAN FINITE ELEMENT

2017 ◽  
Vol 11 (2) ◽  
pp. 131-138
Author(s):  
Setyo Margo Utomo
Keyword(s):  
Safety Factor ◽  
Maximum Stress ◽  
Transverse Load ◽  
Bogie Frame ◽  
Stage Design ◽  
Static Tests ◽  
Static Test ◽  
3D Cad ◽  
Static Testing ◽  
Numerical Order

Bogie is a unity that supports the construction of railway facilities monorail when running on the track. Bogie frame is a construction to support the carbody against imposition. The purpose of this analysis is to determine and ascertain the limits static strength numerical order before the prototype bogie frame through static testing or verification stage design. Stages in this research is the collection of data and bogie drawing APMS of PT.INKA Madiun, and then to identify the 3D CAD model of the structure of the bogie frame, then conducted to determine the boundary conditions for the imposition of simulated static load.Base on standard UIC-615 there are only two types of load that is vertical and transversal, the maximum value is 53 234 and 48 619 N. Result of static testing for static tests with exceptional load, the greatest deformation of 0.5 mm occurs on the balanced wheel, and a maximum stress of 175,97 MPa which lies in the foundation of anti-roll bar, due to transverse load occurring on the pedestal of the anti-roll bar is quite large. Safety factor value that occurs in the area of anti-roll bar is quite low, 1,39.The simulation results for the static testing workload (Static test to Simulate the main in-service load) obtained value of the lowest safety factor of 2.39 with a maximum stress value of 102.26 MPa and deformation of 0,339 mm at the time of load case 8.

scholarly journals State of the art of DSRW test equipment subjected to side loads and equipment proposal for static testing at natural scale

2019 ◽  
Vol 29 (2) ◽  
Author(s):  
Gram Rivas ◽  
Elliot Quispe ◽  
Sandra Santa Cruz
Keyword(s):  
Low Cost ◽  
Full Scale ◽  
Testing Equipment ◽  
Dynamic Tests ◽  
Static Test ◽  
Static Testing ◽  
Out Of Plane ◽  
Seismic Forces ◽  
Tilting Table ◽  
Full Scale Testing

Dry Stone retaining walls, DSRW, are low-cost traditional structures made of stones aimed to stabilize, support backfill and avoid soil erosion. They have massively been used as foundation of dwellings by vulnerable population located in the steeped hills surrounding some Latin-American cities. These walls are built following ancient techniques that are neither well studied nor formally established. Millions of people live in these conditions in seismic zones generating a high-risk situation. Experimental and numerical studies are needed in order to evaluate the reliability of low-cost DSRW and to validate or improve traditional techniques. The objective of this ongoing research is to design and construct a full-scale testing equipment to assess DSRW performance against lateral out-of-plane seismic forces. The methodology consists in the following steps: (1) Review of state-of-art of experimental testing of DSRW, (2) Analysis of failure modes of similar constructions (3) Conceptual and structural design of optimum full-scale testing equipment, (4) Construction planning (blueprints and budget) and (5) Construction and operation. Testing equipment found in technical literature can be classified into two groups according to the applied force: dynamic and static. Forces in dynamic tests are the result of acceleration imposed to the specimen, e.g. shaking tables and centrifuge machines. Forces in static testing are applied by hydrostatic pressure, lateral earth pressure, and specimen´s weight. Applied forces in dynamic tests simulate seismic forces well. On the other hand, it is a high cost solution and requires very specialized staff for operation and maintenance. Static alternatives are more affordable but seismic forces are roughly simulated by static forces. In this work a tilt table is proposed to test full-scale specimens. In this test, the specimen is built in a horizontal table that is slowly rotated.  In this way, a static out-of-plane force acts in each particle of the specimen. The magnitude of the total force is the specimen´s weight multiplied by the sin of the rotating angle. Static test results could be conservative but they could give a good approach to understand DSRW damage accumulation process and failure. Two equipments were proposed: (1) tilting table for monotonic static test and (2) tilting table for cylic test. We compare costs, required area, construction feasibility, and operation manageability. We conclude that both of them are straightforward solutions to assess DSRW performance against out-of-plane lateral forces.

scholarly journals THE DATA ACQUISITION ROLE ON STATIC TEST FOR VALIDATION OF RX320 ROCKET MOTOR DESIGN

2021 ◽  
Vol 6 (1) ◽  
pp. 9-18
Author(s):  
Setiadi Setiadi ◽  
Bagus Wicaksono ◽  
Kurdianto Kurdianto ◽  
Bagus H. Jihad
Keyword(s):  
Data Acquisition ◽  
Numerical Data ◽  
Flight Test ◽  
Rocket Motor ◽  
Chamber Pressure ◽  
Material Strength ◽  
Physical Force ◽  
Static Test ◽  
Static Testing ◽  
Calculation Results

Data Acquisition System has a significant role, especially in static testing of a rocket, determining whether a rocket is declared eligible to fly or not based on the static rocket test. Static testing of the RX320 rocket involves several numerical data instrumentation components, including the Yokogawa DL850 and the CDA900 Signal Conditioner, and the PT750 Pressure sensor. It has functions to accept the physical force that occurs, measure and record the value of the Pressure force in the RX 320 Rocket Chamber at the time Static test during burning time is performed. From the record value of the RX 320 chamber pressure, it can be stated that the RX 320 is suitable for the rocket flight test. The calculation results of the chamber pressure design and the results of measurement and recording of RX320 static test data indicate that the Pressure Chamber RX320 value is still within the safe limits of the RX320 Rocket motor tube material strength.

Sign in / Sign up

Export Citation Format

Share Document