42 Questions 43 Answers 0 Followers
Questions related from Ahmed H. Abdulaziz
I did an experiment on a glass composite thin plate and generated Lamb wave. I increased the stiffness of the plate by forming a sandwich structure. I could find Ao mode with very attenuated...
26 April 2020 1,396 1 View
I found that energy efficiency deals with combustion efficiency, using biomass fuels and stuff like that. Can we link between wind energy and energy efficiency by some means?
08 June 2019 3,005 6 View
I know about mesh density, skewness, wrap angles, and aspect ratio. Per literature, aspect ratio is a quick tool to define quality of mesh. Is there a rule of thumb for acceptable values of...
08 February 2019 7,266 4 View
I use fmincon to minimise weight to stiffness ratio. This ratio is Non linear. I tested this solver by using different initial points Xo. However, results are changeable and dependent on Xo. I am...
02 February 2019 3,192 3 View
I'm a little bit understanding economy. I want to know about the most beneficial way for a country's economy. Sending money from another country in national currency or in foreign currency.
17 January 2019 522 7 View
Bengham Plastics start to flow linearly after reaching a critical shear stress. Assuming this critical shear stress is very small, then approximately, we can consider it behaves like a Newtonian...
25 May 2018 5,354 4 View
I'd like to know the main parameters that should be considered in designing of injection mold. Also, I need to know a source for standardized calculations.
11 February 2018 6,523 3 View
The Elastomeric pads can be used as vibration isolators. I want to know whether there is significant effect of initial compression (pre-loading) of this pads on increasing the dynamic stiffness or...
07 August 2017 2,689 5 View
I'm an engineer, however, I'm interested in knowing a little bit about self-healing mechanisms in our bodies for small scratches and wounds
06 February 2017 8,729 1 View
Instead of using acoustics emissions systems or ultrasonic systems, is it possible to use microphones in detecting defects of a fibreglass composites?
16 January 2017 6,783 4 View
I'm carrying out an experimental modal analysis on the fixture of rotating beams. The rotary beams are attached to a D/C motor and I measured the vibrations at the fixture of the motor. I got...
05 May 2016 8,644 8 View
I'm a mechanical engineer. I'm interested in learning about optimization methods and how we can implement them in a problem. I want to apply one of them in structural to increase rigidity to mass...
02 March 2016 6,869 11 View
I used ANSYS Workbench in the modal analysis of a structural frame. The structure is imported as solid body NOT surface model. I meshed it using mapped mesh option and hexa\tetra elements....
13 February 2016 3,658 4 View
I perform a fatigue test on a wind turbine blade. I measure the natural frequency after certain number of cycles. I've plotted a graph between number of cycles and the natural frequency and I...
15 August 2015 2,615 8 View
I have a GFRP product, macro cracks appeared in that product...I want to avoid these cracks knowing that the glass fiber laminae were designed to survive loads however, it fails !!!!
19 March 2015 6,186 10 View
I have a wind turbine blade consists of steel chassis and outer surface of fiber glass plies, I want to perform bending test on it. I want to use acoustics emission during the test to detect the...
23 February 2015 9,647 3 View
I have a wind blade. I want to perform a fatigue test on it. Some standards state that to accelerate the fatigue, one can use excitation with frequency very near to the natural frequency of the...
21 January 2015 3,782 6 View
I have a cantilever steel beam of 1m length. I want to determine the strain near fixation due to the bending moment of a dead weight on the tip of the beam. I plan to place 3 strain gauges near...
15 January 2015 4,665 4 View
I want to know if there is any formula to calculate the clearance between tip of blade and tower so when the blade deflects it won't touch the tower.
09 January 2015 8,466 3 View
A wind blade consists of steel chassis and composite laminae as outer surface. I want to make bending stress on the blade. It fixed from end as cantilever. I will put strain gauge rosette near...
29 December 2014 4,903 3 View
I want to apply cyclic load on the blade to inspect it under fatigue loading. I want to save the blade and I do not want to causes failure to it. I'm looking for a methodology that can help me...
27 December 2014 4,185 6 View
I want to use Acoustic emission in testing wind blade. I need a standard that explains the procedure.
11 December 2014 4,308 4 View
I have a 7m HAWT blade. I want to make static bending test on it. I will draw these graphs Force vs tip deflection bending moment vs strain Are these enough or there are some other phenomena to...
10 December 2014 8,663 2 View
I want to obtain the center of gravity COG of HAWT blade before testing it.
05 December 2014 8,092 4 View
In static bending tests, I use normal and tangential forces to get tip deflection without converting them to lift an drag. Is it incorrect?
01 December 2014 2,077 3 View
I have a distorted model to a prototype. Dimensional scale for thickness is not same as other geometrical dimensions. I found that there is procedure to use distorted model to predict the...
05 October 2014 4,546 4 View
I need to get the area moment of inertia.
02 October 2014 7,967 5 View
I used Buckinghum Pi theorem. I derived pi groups for the natural frequency phenomena. The first pi group was function of (natural frequency, E,Rho,Cantilever length) The second pi group was...
29 September 2014 9,997 3 View
I want to learn deeply the optimization methods using genetic algorithms, It is the first time and I want to learn it to optimize design of wind turbines
14 September 2014 4,044 3 View
I want to use Buckinghum Pi Theorem to relate a similitude of the blade to the prototype blade. I began as stating the natural frequency is function of ( Young's Modulus, Length of the blade,...
05 September 2014 329 2 View
I want to predict the data of large blade from small similitude. I need scaling up relations to do that. The similitude length = 300 mm The prototype length = 7000 mm
24 August 2014 9,960 4 View
I have an error as shown , how can I delete the error messages that violate the memory span?
07 August 2014 4,929 3 View
I need to calculate the deflection of a 7m blade, and I've tried to simplify the blade as tapered beam and then derived deflection low for it , but this law gave deflection half of the...
10 July 2014 8,905 8 View
I was working on getting non dimensional pi-groups for a model and scaled down similitude of cantilevers. For a cantilever : I got a pi1 =Deflection "u"/length"l" So i used u/l )model = u/l...
28 June 2014 7,798 1 View
I have analysed the unsteady forces calculated by FAST v7 to get the periodical unsteady forces to check the fatigue due to them. I got fn and ft for 30 station on the HAW blade of 7m...
19 June 2014 5,592 3 View
I have done a vibrational analysis on an orthotropic ABS plastic wind turbine blade, it is required to set its 9 elastic properties. I searched and got a range for longitudinal modulus of ABS then...
12 May 2014 4,611 4 View
I made experimental modal analysis and an FE modal analysis. I want to use the statistical indicator MAC. I have to use the table and check the value of this indicator. I do not know where can...
29 April 2014 2,406 1 View
I have designed a 7 meter HAW blade and modelled it using Ansys APDL. I'd like to validate the results so I'm think of scaling down this blade to a smaller similitude !
26 April 2014 2,382 2 View
I have a model of a wind turbine blade made of abs polymer. I made experimental measurements and did ansys simulation to get the atural frequencies and mode shapes. The results in the first mode...
14 April 2014 7,355 5 View
I have modeled the blade in ansys and found it's mode shapes. I want to validate the results with simple and scientific means because I cannot manufacture a 7 m blade. What do you suggest?
04 March 2014 5,439 3 View
I need to compare my natural frequencies with other's model to check if my frequencies lie within a reasonable range or not.
26 February 2014 562 1 View
I have created a simple model, a plate surface. I fixed one side with zero for all 6 degrees of freedom and other sides are free. I want to make Modal analysis and I made it with results for the...
22 February 2014 10,016 3 View
