scholarly journals Analysis of the Performance Variation Mechanism of MEMS Suspended Inductors under Mechanical Shock

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 686 ◽  
Author(s):  
Li ◽  
Xu ◽  
Li
Keyword(s):  
Theoretical Analysis ◽  
Equivalent Model ◽  
Mechanical Shock ◽  
Test Results ◽  
Lumped Element ◽  
Performance Variation ◽  
Inductor Coil ◽  
Parasitic Effect ◽  
Variation Mechanism ◽  
Micro Electromechanical System

Micro-electromechanical system (MEMS) suspended inductors have been widely studied in recent decades because of their excellent radio frequency performance. However, the deformation of the inductor coil and the performance variation usually occur to the MEMS suspended inductors when the inductors are under mechanical shock. Few studies have been carried out on the performance variation of MEMS suspended inductors under shock. In this study, the mechanism of the performance variation of MEMS suspended inductors under mechanical shock is analyzed by combining theoretical analysis and experiments. A theoretical analysis based on the lumped-element equivalent model is presented and shock tests are carried out. The shock tests show that the main reason of the MEMS suspended inductor performance variation after mechanical shock is the variation of the substrate parasitic effect, which is caused by the variation of the suspension height of the inductor after shock. The test results agree with the theoretical analysis.

Upgrading of Tubular Heat Exchangers by the Helical Spacer Method and Evaluation

2002 ◽  
Author(s):  
F. L. Eisinger ◽  
R. E. Sullivan
Keyword(s):  
Theoretical Analysis ◽  
Acoustic Wave ◽  
Heat Exchangers ◽  
Test Results ◽  
Vibration Testing ◽  
Safe Operation ◽  
Shell Side ◽  
Full Load ◽  
Post Modification ◽  
Side Flow

The tubular heat exchangers described exhibited a sensitivity to flow-induced tube vibration at about 50% of their design shell-side flow. Following a detailed theoretical analysis, the heat exchangers were modified by the helical spacer method providing additional tube supports in-between the existing support plates and in the U-bend. This modification aimed at allowing the heat exchangers to operate safely and reliably at full load, including a 25% overload. Post modification sound and vibration testing was performed which confirmed the adequacy of the modification. The test results showed however, that at the overload condition, an unusual acoustic wave inside the shell was developing. It was determined that this wave would not be harmful to the safe operation of the heat exchangers. The paper will discuss the findings in more detail.

The theoretical analysis and simulation of acoustic absorber for nonlinear shunted loudspeaker

2021 ◽  
Vol 263 (6) ◽  
pp. 388-393
Author(s):  
Wenjiang Wang ◽  
Xianhui Li ◽  
Junjuan Zhao ◽  
Peng Zhang ◽  
Xinyun Li ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Sound Absorption ◽  
Nonlinear Term ◽  
Equivalent Model ◽  
Frequency Bandwidth ◽  
Nonlinear Circuit ◽  
Van Der Pol ◽  
Absorption Bandwidth ◽  
Simulation Results ◽  
Different Time Scales

In this paper, a nonlinear electroacoustic absorber based on a tunable loudspeaker is proposed to broaden its sound absorption bandwidth. The main mechanism is a nonlinear circuit is coupled at loudspeaker's terminal. A series of theoretical analysis and simulation work are carried out in this paper. The equivalent model is composed of a linear term describing the loudspeaker and a nonlinear term of a coupled Duffing-van Der Pol bistable circuit. The invariant manifold method is used to solve different time scales. The analysis and simulation results show that the nonlinear circuit can widen the frequency bandwidth of the structure.

Estimation of Performance Variation of Coal Fired Boilers Cofired With Biomass: Development of a Predicting Tool

2006 ◽  
Author(s):  
Sudipta De ◽  
Mehrzad Kaiadi ◽  
Mohsen Assadi
Keyword(s):  
Customer Service ◽  
Pilot Plant ◽  
Model Development ◽  
Test Results ◽  
Performance Variation ◽  
Future Improvement ◽  
Pilot Plant Test ◽  
Plant Test ◽  
Biomass Cofiring ◽  
Available Information

Biomass cofiring in existing coal fired boilers has emerged as one of the most prospective technologies in order to address voluntary reduction of green house gases and other emissions, potential portfolio standards, customer service etc. within the context of deregulations. Pilot plant test results have confirmed the potential of biomass cofiring with coal for commercial use. However, being a new and developing technology, there is hardly any tool available for estimation of variation in performance of an existing coal fired boiler due to its retrofitting for biomass cofiring. A predicting tool is developed to estimate this performance variation using available information of pilot plant test results in literature or from data of plant operating with biomass. In order to incorporate future available information, this is developed in a flexible environment of Model Development Kit (MDK) of IPSEpro, a commercially available heat and mass balance program. Development of the models for this predicting tool as well as its limitations and possible future improvement has been discussed in this paper. Some results regarding estimation of change in efficiency, emissions and associated costs using this developed predicting tool has been presented.

High Pressure Test Results of a Catalytically Assisted Ceramic Combustor for a Gas Turbine

1999 ◽  
Vol 121 (3) ◽  
pp. 422-428 ◽  
Author(s):  
Y. Ozawa ◽  
Y. Tochihara ◽  
N. Mori ◽  
I. Yuri ◽  
T. Kanazawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Catalytic Combustion ◽  
Ceramic Fiber ◽  
Outlet Temperature ◽  
Mechanical Shock ◽  
Test Results ◽  
Ceramic Tiles ◽  
Combustion Gas ◽  
Ceramic Liner

A catalytically assisted ceramic combustor for a gas turbine was designed to achieve low NOx emission under 5 ppm at a combustor outlet temperature over 1300°C. This combustor is composed of a burner system and a ceramic liner behind the burner system. The burner system consists of 6 catalytic combustor segments and 6 premixing nozzles, which are arranged in parallel and alternately. The ceramic liner is made up of the layer of outer metal wall, ceramic fiber, and inner ceramic tiles. Fuel flow rates for the catalysts and the premixing nozzles are controlled independently. Catalytic combustion temperature is controlled under 1000°C, premixed gas is injected from the premixing nozzles to the catalytic combustion gas and lean premixed combustion over 1300°C is carried out in the ceramic liner. This system was designed to avoid catalytic deactivation at high temperature and thermal and mechanical shock fracture of the honeycomb monolith of the catalyst. A combustor for a 10 MW class, multican type gas turbine was tested under high pressure conditions using LNG fuel. Measurements of emission, temperature, etc. were made to evaluate combustor performance under various combustion temperatures and pressures. This paper presents the design features and the test results of this combustor.

Research on Methods for Elastic Stiffness of Multi-Ribbed Slab Structure

2010 ◽  
Vol 97-101 ◽  
pp. 1736-1740
Author(s):  
Qi Zhang ◽  
Dong Bo Li ◽  
Qian Feng Yao ◽  
Dong Zhao
Keyword(s):  
Time History ◽  
Elastic Stiffness ◽  
Structural Effect ◽  
Time History Analysis ◽  
Equivalent Model ◽  
Test Results ◽  
History Analysis ◽  
Set Up

Considering the influence of the flange and rib column, the equivalent model of multi-ribbed slab is set up by the theory based on the strengthening isotropism fiber. This model is simple, highly precise and strongly applicable through comparing analyzing results with test results. Besides, the calculated formulate is set up on the basis of the whole structural effect and space work, which offers the prerequisite for elastic time history analysis of the structure.

Design-Oriented Analysis of Slow-Scale Bifurcations in Single Phase DC–AC Inverters via Autonomous Transformation Approach

2017 ◽  
Vol 27 (06) ◽  
pp. 1750086 ◽  
Author(s):  
Hao Zhang ◽  
Honghui Ding ◽  
Chuanzhi Yi
Keyword(s):  
Theoretical Analysis ◽  
Circuit Design ◽  
Single Phase ◽  
Underlying Mechanism ◽  
System Stability ◽  
Equivalent Model ◽  
Eigenvalue Sensitivity ◽  
Physical Experiments ◽  
Averaged Model ◽  
Theoretical Results

This paper deals with the design-oriented analysis of slow-scale bifurcations in single phase DC–AC inverters. Since DC–AC inverter belongs to a class of nonautonomous piecewise systems with periodic equilibrium orbits, the original averaged model has to be translated into an equivalent autonomous one via a virtual rotating coordinate transformation in order to simplify the theoretical analysis. Based on the virtual equivalent model, eigenvalue sensitivity is used to estimate the effect of the important parameters on the system stability. Furthermore, theoretical analysis is performed to identify slow-scale bifurcation behaviors by judging in what way the eigenvalue loci of the Jacobian matrix move under the variation of some important parameters. In particular, the underlying mechanism of the slow-scale unstable phenomenon is uncovered and discussed thoroughly. In addition, some behavior boundaries are given in the parameter space, which are suitable for optimizing the circuit design. Finally, physical experiments are performed to verify the above theoretical results.

Test Results on the ARL 19 Supersonic Blade Cascade

1988 ◽  
Vol 110 (4) ◽  
pp. 450-455 ◽  
Author(s):  
A. Fourmaux ◽  
R. Gaillard ◽  
G. Losfeld ◽  
G. Meauze´
Keyword(s):  
Theoretical Analysis ◽  
Data Reduction ◽  
Experimental Results ◽  
Test Facility ◽  
Experimental Program ◽  
Test Model ◽  
Test Results ◽  
Blade Cascade

This paper presents the ONERA contribution in a joint experimental program on the aerodynamics of supersonic airfoil cascades. The first part deals with the specific ONERA way of running cascade tests: description of the test facility, the test model, the instrumentation, and data reduction. Then, after a brief theoretical analysis of the ARL 19 cascade, some experimental results are presented and discussed.

Design Method on Shear Behavior of Single Tapping Screw Connections in Cold-Formed Thin-Wall Steel Structures

2013 ◽  
Vol 351-352 ◽  
pp. 691-694 ◽  
Author(s):  
Shen Wei Wang ◽  
Cheng Jiang Wang
Keyword(s):  
Theoretical Analysis ◽  
Steel Plate ◽  
Design Method ◽  
Sheet Steel ◽  
Steel Structures ◽  
Shear Capacity ◽  
Thin Wall ◽  
Plate Steel ◽  
Test Results ◽  
Plate Connections

In order to investigate the design method of single tapping screw connections between steel plate and non-steel plate and the applicability of calculating the shear capacity of single tapping screw connections with sheet steel under 2mm according to Chinese code Technical code for design of cold-formed thin-wall steel structures(GB50018-2002),theoretical analysis was carried out on single tapping screw connections, which were distinguished by connection forms called steel plate-steel plate connections and steel plate-non-steel plate connections. The results show that: Chinese code GB50018-2002 is suited to calculate the shear capacity of single tapping screw connections with sheet steel under 2mm and the results are safe compared with test results. The design method of single tapping screw connections between steel plate and non-steel plate is given on the basis of test results.

Drop Reliability of Corner Bonded CSP in Portable Products

2003 ◽  
Author(s):  
Guoyun Tian ◽  
Yueli Liu ◽  
Pradeep Lall ◽  
R. Wayne Johnson ◽  
Sanan Abderrahman ◽  
...  
Keyword(s):  
Capillary Flow ◽  
Drop Test ◽  
Mechanical Shock ◽  
Solder Paste ◽  
Test Results ◽  
Mechanical Coupling ◽  
Small Areas ◽  
Common Solution ◽  
Four Corners ◽  
Capillary Underfill

The use of CSPs has expanded rapidly, particularly in portable electronic products. Many CSP designs will meet the thermal cycle or thermal shock requirements for these applications. However, mechanical shock (drop) and bending requirements often necessitate the use of underfills to increase the mechanical strength of the CSP-to-board connection. Capillary flow underfills processed after reflow, provide the most common solution to improving mechanical reliability. However, capillary underfill adds board dehydration, underfill dispense, flow and cure steps and the associated equipment to the assembly process. Corner bonding provides an alternate approach. Dots of underfill are dispensed at the four corners of the CSP site after solder paste print, but before CSP placement. During reflow the underfill cures, providing mechanical coupling between the CSP and the board at the corners of the CSP. Since only small areas of underfill are used, board dehydration is not required. This paper examines the manufacturing process for corner bonding including dispense volume, CSP placement and reflow. Drop test results are then presented. A conventional, capillary process was used for comparison of drop test results. Test results with corner bonding were intermediate between complete capillary underfill and non-underfilled CSPs. Finite element modeling results for the drop test are also included.

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