scholarly journals Interactive Multimode Blade Impact Analysis

1982 ◽  
Vol 104 (2) ◽  
pp. 286-295
Author(s):  
A. Alexander
Keyword(s):  
Computer Program ◽  
Impact Analysis ◽  
Impact Resistance ◽  
Local Deformation ◽  
Mode Shapes ◽  
Turbine Engine ◽  
Impact Area ◽  
Fan Blade ◽  
Mode Beam ◽  
The Impact

This paper describes the theoretical methodology used in developing an analysis for the response of turbine engine fan blades subjected to soft body (bird) impacts and the computer program that was developed using this methodology as its basis. This computer program is an outgrowth of two programs that were previously developed for the purpose of studying problems of a similar nature (a three-mode beam impact analysis and a multimode beam impact analysis). The present program utilizes an improved missile model that is interactively coupled with blade motion which is more consistent with actual observations. It takes into account local deformation at the impact area, blade camber effects, and the spreading of the impacted missile mass on the blade surface. In addition, it accommodates plate-type mode shapes. The analysis capability in this computer program represents a significant improvement in the development of the methodology for evaluating potential fan blade materials and designs with regard to foreign object impact resistance.

scholarly journals Interactive Multi-Mode Blade Impact Analysis

1981 ◽  
Author(s):  
A. Alexander
Keyword(s):  
Computer Program ◽  
Impact Analysis ◽  
Impact Resistance ◽  
Local Deformation ◽  
Mode Shapes ◽  
Turbine Engine ◽  
Fan Blade ◽  
Mode Beam ◽  
The Impact ◽  
Multi Mode

This paper describes the theoretical methodology used in developing an analysis for the response of turbine engine fan blades subjected to soft body (bird) impacts and the computer program that was developed using this methodology as its basis. This computer program is an outgrowth of two programs that were previously developed for the purpose of studying problems of a similar nature (a three-mode beam impact analysis and a multi-mode beam impact analysis). The present program utilizes an improved missile model that is interactively coupled with blade motion which is more consistent with actual observations. It takes into account local deformation at the impact area, blade camber effects, and the spreading of the impacted missile mass on the blade surface. In addition, it accommodates plate-type mode shapes. The analysis capability in this computer program represents a significant improvement in the development of the methodology for evaluating potential fan blade materials and designs with regard to foreign object impact resistance.

Elementary Three-Dimensional Interactive Rotor Blade Impact Analysis

1976 ◽  
Vol 98 (4) ◽  
pp. 480-486 ◽  
Author(s):  
R. W. Cornell
Keyword(s):  
Impact Analysis ◽  
Impact Force ◽  
Three Dimensional ◽  
Soft Or ◽  
Mass System ◽  
Centrifugal Stiffening ◽  
Modes Of Vibration ◽  
Fan Blade ◽  
The Impact ◽  
Good Agreement

A theoretical analysis is presented which defines the loading and response of a rotor fan blade due to soft or frangible impacts in terms of the three fundamental modes of vibration by representing the blade as a lumped, spring-mass system. The analysis includes the effects of centrifugal stiffening, blade twist, retention stiffness and orientation, damping, and blade motion and deflection on the impact force. The features, solution, program, and applications of this analysis are reviewed, and the results are compared with those from a number of blade and specimen tests and found to be in good agreement.

Research on the Impact Resistance of the Periodic Helicoidal Multilayer Bionic Structure Based on Osteon Microstructure

2021 ◽  
Author(s):  
Yuxi Liu ◽  
Ai-hua Li ◽  
Bin Chen ◽  
Yan-hua Li
Keyword(s):  
Energy Dissipation ◽  
Impact Analysis ◽  
Impact Damage ◽  
Impact Resistance ◽  
Helix Angle ◽  
Collagen Fibers ◽  
Composite Models ◽  
Helicoidal Structure ◽  
The Impact ◽  
Mineralized Collagen

Abstract Background: As a typical biological material, bone have excellent mechanical properties and plays an important role in supporting the animal body and protecting organs, osteon is an important part of bone. It is found that the osteon is composed of thin and thick lamellae which are periodic and approximately concentric, every 5 lamellae is a cycle, the periodic helix angle of mineralized collagen fibers in two adjacent sub-lamellae is 30°. Four biomimetic composite models with different fiber helix angles were established and fabricated according to the microstructure of mineralized collagen fibers in osteon. Based on the impact analysis of four kinds of bionic composite models, the effects of the fiber periodic helicoidal structure on the impact resistance and energy dissipation of multi-layer bionic composite were investigated. Results: The analysis results show that the fiber helix angle affects the impact damage resistance and energy dissipation of multi-layer fiber reinforced composites. Among the four kinds of multi-layer composite models, the composite model with helix angle of 30° has better comprehensive ability to resist impact damage. The test results show that the impact damage area of the specimen with 30° helix angle is smallest among the four types of bionic specimens, which is consistent with the results of finite element impact analysis. Furthermore, in the case of no impact damage, the smaller the fiber helix angle is, the more uniform the stress distribution is and more energy is dissipated in the impact process. Conclusions: The periodic helicoidal structure of mineralized collagen fibers in osteon are the result of natural selection of biological evolution. This structure can effectively improve the ability of cortical bone to resist external impact. The research results can provide useful guidance for the design and manufacture of high-performance and strong impact resistant biomimetic composites.

Impact of Operating and Health Conditions on Aero Gas Turbine: Hot Section Creep Life Using a Creep Factor Approach

2010 ◽  
Author(s):  
M. F. Abdul Ghafir ◽  
Y. G. Li ◽  
R. Singh ◽  
K. Huang ◽  
X. Feng
Keyword(s):  
Gas Turbine ◽  
Impact Analysis ◽  
Influencing Factor ◽  
Operating Conditions ◽  
Health Conditions ◽  
Creep Life ◽  
Turbine Engine ◽  
Model Engine ◽  
Life Consumption ◽  
The Impact

A thorough assessment of component life is very important to ensure both the safety and economics of gas turbine operation. As a component’s life given by OEM is based on certain ambient and operating conditions, its actual life may vary substantially when the ambient, operating and engine health conditions change. Therefore possessing knowledge on how those conditions affect actual component life will be valuable in making informed maintenance decisions, maximising operation effectiveness and cutting down operating costs. In this paper, an impact analysis on component creep life due to different operating and engine health conditions using an introduced Creep Factor is performed, which aims to provide useful insights on the relationship between gas turbine performance change and hot section component’s creep life. As the Creep Factor is defined as the ratio between the actual creep life and a reference creep life at a user-defined condition, the magnitude of the impact can be quantified with the change of the Creep Factor. The developed creep life analysis approach was applied to a model single spool turboshaft gas turbine engine operated at various operating and health conditions. A physics-based model combined with the Creep Factor approach was then used to estimate the creep life variation of the high pressure turbine of the model engine. The results showed that for a clean engine, the change in the rotational speed has given the highest impact on the creep life consumption. Also the presence of blade cooling and component degradation is seen to significantly reduce the blade’s creep life and as the degradation effects are combined, the degree of reduction increases even more. It also shows that the Creep Factor is good indicator of creep life consumption and provides a good technique to rank the influencing factor according to the threat they imposed.

Impact Analysis of Plates Using Quasi-Static Approach

1997 ◽  
Vol 119 (3) ◽  
pp. 376-381 ◽  
Author(s):  
S. Shivaswamy ◽  
H. M. Lankarani
Keyword(s):  
Impact Analysis ◽  
Local Deformation ◽  
Contact Forces ◽  
Stress Wave Propagation ◽  
Rigid Base ◽  
Deformation Model ◽  
Stiff Systems ◽  
Stiff System ◽  
Nonlinear Force ◽  
The Impact

Impact analyses suffer from several practical limitations which limit their application to predict the approximate magnitude of the various phenomena involved. The transient force deformation response of a body subjected to impact can be explained accurately using the stress wave propagation theory. As this approach is complicated, a simpler approach utilizing a quasi-static equilibrium condition can be employed. Nonlinear force-deformation Hertzian relations can be used for the impact analysis. These relations though can not explain the energy dissipation and permanent deformations encountered during the impact. This necessitates independent nonlinear force deformation relations for compression and restitution phases of impact. In this paper, modeling of contact forces during impact on stiff systems (systems which do not undergo gross deformation but experience only local deformation) has been presented. Experiments were conducted on stiff systems to verify the methodology. A plate which is fixed on a rigid base and clamped completely represents a stiff system. Hence experiments were conducted on Aluminum and Steel plates to simulate impact on stiff systems for the verification of the proposed models. The theoretical results matched well with the experimental results. A nonlinear force deformation model with independent relations for compression and restitution phases was found to be a suitable approach to analyze impact problems.

The Impact of a Potential Public/Private Initiative on a Defined Region of the South Suburban Chicago Metropolitan Area

2019 ◽  
pp. 14-32
Keyword(s):  
Supply Chain ◽  
Economic Impact ◽  
Impact Analysis ◽  
Census Data ◽  
Economic Benefits ◽  
Local Economy ◽  
Market Area ◽  
State And Local ◽  
The University ◽  
The Impact

The university is considered one of the engines of growth in a local economy or its market area, since its direct contributions consist of 1) employment of faculty and staff, 2) services to students, and supply chain links vendors, all of which define the University’s Market area. Indirect contributions consist of those agents associated with the university in terms of community and civic events. Each of these activities represent economic benefits to their host communities and can be classified as the economic impact a university has on its local economy and whose spatial market area includes each of the above agents. In addition are the critical links to the University, which can be considered part of its Demand and Supply chain. This paper contributes to the field of Public/Private Impact Analysis, which is used to substantiate the social and economic benefits of cooperating for economic resources. We use Census data on Output of Goods and Services, Labor Income on Salaries, Wages and Benefits, Indirect State and Local Taxes, Property Tax Revenue, Population, and Inter-Industry to measure economic impact (Implan, 2016).

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

Impact Analysis of the Mechanization Program for Tribal Paddy Farmers of Goa

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
MATHALA JULIET GUPTA ◽  
ASHISH M. PITRE ◽  
SUMATI CHAVAN PANDURNAG ◽  
SALONI SALIL VANJARI
Keyword(s):  
Impact Analysis ◽  
Field Capacity ◽  
Significant Saving ◽  
Manual Methods ◽  
Paddy Farmers ◽  
The Impact ◽  
And Training

This paper assessed the impact of the mechanization of the 8 tribal paddy farmers’ groups of Goa benefited in the year 2011 through the Tribal sub-plan program of ICAR-CCARI through results of surveys conducted in 2012 and 2015. Shift to mechanization among beneficiaries was significant in power tillers (64-100%) but less in power reapers(0-91%). Also significant saving in manpower (Power tillers:33.3% to 60%, power reapers: 33.3% to 83.3%), , time (field capacity increased (power tillers : 41.7% to141%, power reapers :58.1% to 912.8%) and cost(power tillers :44.7% to 59.1%, power reapers : 57.8% to 82.9%) was reportedthrough the use of equipment as compared to desi plough or manual methods of harvesting. Some constraints like lack of access roads and training in use and maintenance of the equipment were reported by the beneficiary farmers.

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

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