Mechanical performance of structurally optimized AlSi7 aluminum foams - an experimental study

2014 ◽  
Vol 45 (12) ◽  
pp. 1061-1071 ◽  
Author(s):  
D. Lehmhus ◽  
M. Busse
Keyword(s):  
Experimental Study ◽  
Mechanical Performance ◽  
Aluminum Foams

Study of Fault Self-Recovery and Seal Improvement for Centrifugal Compressor

2010 ◽  
Author(s):  
Weimin Wang ◽  
Jinji Gao ◽  
Yan Li ◽  
Shuangxi Li
Keyword(s):  
Experimental Study ◽  
Centrifugal Compressor ◽  
Thrust Bearing ◽  
Mechanical Performance ◽  
High Reliability ◽  
Relevant Information ◽  
Axial Displacement ◽  
Oil Film ◽  
Dry Gas Seal ◽  
Low Leakage

For centrifugal compressor, discharge or suction pressure variations due to process fluctuations or balance drum seal degradation can result in rotor thrust increasing which may jeopardize thrust bearing and compressor’s reliability. Also, the leakage flow through balance drum seal can seriously affect the efficiency of compressor. Summarizing the characteristic of axial displacement fault about centrifugal compressor and analyzing the mechanical performance of tilt pads thrust bearing, theory of axial displacement fault self-recovery is presented and realized through experimental study. The method presented in this paper monitors the stiffness of oil film and identifies the reason of axial displacement increasing. Also the low leakage feature of Dry-Gas-Seal (DGS), high reliability of labyrinth, and the feasibility of upgrading existing structure are taken into account at the same time to design a combined labyrinth-dry gas seal system on the balancing drum. Based on the combined seal system, a Fault Self-Recovering (FSR) mechanism for the fault of rotor axial displacement is introduced to assure the minimum oil film thickness was ensured in real time. The modern Computational Fluid Dynamics (CFD) and experimental study were used to validate this concept. The result and relevant information indicate that the method can realize axial displacement fault self-recovering effectively and the combined sealing system could improve the efficiency of the centrifugal compressor about four percent.

scholarly journals Effects of Different Interface Forms on Mechanical Properties of Steel Self-Compacting Concrete Composite Beams

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Chengzhi Wang ◽  
Xin Liu ◽  
Wei Liu ◽  
Zhiming Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Bearing Capacity ◽  
Composite Structure ◽  
Mechanical Performance ◽  
Complex Structure ◽  
Self Compacting Concrete ◽  
Element Analysis ◽  
Shear Connectors ◽  
Fea Model

In the water resources allocation project in Pearl River Delta, in order to optimize the structural design, the deep buried tunnel adopts the composite lining structure. However, the weakest link in a complex structure is the connection between two different interfaces. This paper reports the findings of an experimental study that was undertaken to investigate the interface mechanical performance of steel self-compacting concrete composite structure subjected to cyclic loads. In this study, different shear connectors are considered, and six different specimens were designed and tested, respectively. The test is used to research the effect of the different shear connectors on the bearing capacity and interface mechanical properties of composite structure in an experimental study. According to these test results, a detailed analysis was carried out on the relationships, such as the stress-strain and load-displacement relationships for the specimen. These tests show that the shear connectors will significantly enhance the bearing capacity and interface mechanical properties of the composite structure. Among them, the comprehensive performance of the specimens using the stud-longitudinal ribs shear connectors is the best. Additionally, a finite element analysis (FEA) model was developed. The comparison of the simulation results with the experimental results shows that this FEA is applicable for this type of experiment.

Structure and Deformation of Gradient Metal Foams Produced by Machining

2019 ◽  
Author(s):  
H. Qiao ◽  
T. G. Murthy ◽  
C. Saldana
Keyword(s):  
Aluminum Foam ◽  
Mechanical Performance ◽  
Metal Foams ◽  
Aluminum Foams ◽  
Open Cell ◽  
Computed Tomographic ◽  
Surface Gradient ◽  
Structure Changes

Abstract The effects of surface structure on mechanical performance for open-cell aluminum foam specimens was investigated in the present study. A surface gradient for pore structure and diameter was introduced into open cell aluminum foams by machining-based processing. The structure changes in the strut and pore network were evaluated by computed tomography characterization. The role of structure gradients in affecting mechanical performance was determined using digital volume correlation and in situ compression within the computed tomographic scanner. These preliminary results show that the strength of these materials may be enhanced through surface structural gradients.

Preparation of High Performance Aluminum Foam Using Carbon Fibers as Stabilizing Additive

2011 ◽  
Vol 308-310 ◽  
pp. 53-57
Author(s):  
Zhuo Kun Cao ◽  
Huan Liu ◽  
Jin Jing Du ◽  
Guang Chun Yao
Keyword(s):  
Mechanical Property ◽  
Carbon Fibers ◽  
High Performance ◽  
Aluminum Foam ◽  
Mechanical Performance ◽  
Metallic Foams ◽  
Aluminum Foams ◽  
Foam Structure ◽  
Stable Foam ◽  
Fiber Fraction

Carbon fibers are used as novel stabilizing additives for aluminum foams production at the aim of manufacturing metallic foams of high mechanical performance. The effect of carbon fiber fraction on the foam structure and mechanical property is studied in the present paper. Results shows that the change in foam structure can be slowed down by increasing fiber fraction, which would led to more stable foam. The yield strength of aluminum foams increase with fiber fraction, but the foams are also getting brittle. High performance aluminum foams can also prepared by using aluminum alloy as start material, and the resulting foams show much higher compressive strength than that of commercial aluminum foams.

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