Preferred Language
Articles
/
alkej-494
Free Vibration Analysis of Laminated Composite Plates with General Boundary Elastic Supports Under Initial Thermal Load
...Show More Authors

Free vibration behavior was developed under the ratio of critical buckling temperature of laminated composite thin plates with the general elastic boundary condition. The equations of motion were found based on classical laminated plate theory (CLPT) while the solution functions consists of trigonometric function and a continuous function that is added to guarantee the sufficient smoother of the so-named remaining displacement function at the boundaries, in this research, a modified Fourier series were used, a generalized procedure solution was developed using Ritz method combined with the imaginary spring technique. The influences of many design parameters such as angles of layers, aspect ratio, thickness ratio, and ratio of initial in- plane thermal load in addition to different boundary conditions on the natural frequencies of laminated plate is analyzed. In general, the changes of fundamental natural frequency is inversely proportional with the ratio of thermal buckling load, also most parameters aspect ratio effect on the natural frequency about 35 – 40%. The present results were compared with those obtained by other researchers, and show good agreement.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Aug 01 2022
Journal Name
Engineering, Technology & Applied Science Research
Castellated Beams with Fiber-Reinforced Lightweight Concrete Deck Slab as a Modified Choice for Composite Steel-Concrete Beams Affected by Harmonic Load
...Show More Authors

The behavior investigation of castellated beams with fiber-reinforced lightweight concrete deck slab as a modified choice for composite steel-concrete beams affected by harmonic load is presented in this study. The experimental program involved six fixed-supported castellated beams of 2140mm size. Three types of concrete were included: Normal Weight Concrete (NWC), Lightweight Aggregate Concrete (LWAC), and Lightweight Fiber-Reinforced Aggregate Concrete (LWACF). The specimens were divided into two groups: the first comprised three specimens tested under harmonic load effect of 30Hz operation frequency for 3 days, then the residual strength was determined through static load application. The second group included three specimens ide

... Show More
Crossref (12)
Crossref
Publication Date
Tue Apr 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Study the eifficiency of land transportation in the economic development under transference to the economic market, the general company of land transportation – case study –
...Show More Authors

Land Transport regards a main element in the In Fra – structure of the national economy where distance and time shortness, open new opportunities of work, develop the different regions and rise the standard of living….

It is necessary to emphasize that the circumastances surrounding Iraq such as wars, economic sanctions, blockade occupation effected negatively upon economic Indicators of land Transportion including Value of output Value added contraction of Investment allocation and  Investment expend tuer and the period of implementation and fulfillment of the projects of Land Transport to be ready to offer their service in underdeveloped country Like Iraq aiming to satisfy Fast and acomprehensi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Numerical Analysis of Double Diffusive Laminar Natural Convection in a Right Angle Triangular Solar Collector
...Show More Authors

A numerical study of the double-diffusive laminar natural convection in a right triangular solar collector has been investigated in present work. The base (absorber) and glass cover of the collector are isothermal and isoconcentration surfaces, while the vertical wall is considered adiabatic and impermeable. Both aiding and opposing buoyancy forces have been studied. Governing equations in vorticity-stream function form are discretized via finite-difference method and are solved numerically by iterative successive under relaxation (SUR) technique. Computer code for MATLAB software has been developed and written to solve mathematical model. Results in the form of streamlines, isotherms, isoconcentration, average Nusselt, and average Sherw

... Show More
View Publication Preview PDF
Publication Date
Sun Oct 14 2018
Journal Name
Industrial Lubrication And Tribology
Thermal stress analysis of dry friction clutches
...Show More Authors
Purpose

The purpose of this paper is to present an approach to compute accurately the distributions of the frictional heat generated, contact pressure and thermal stresses at any instant during the sliding period (heating phase) of the single-disc friction clutch system works in the dry condition and the complex interaction among them.

Design/methodology/approach

Numerical work was achieved using the developed elastic and thermal finite element models (axisymmetric models) to simulate the engagement of the single-disc friction clutch system.

... Show More
View Publication
Scopus (14)
Crossref (14)
Scopus Clarivate Crossref
Publication Date
Wed Feb 03 2021
Journal Name
Structural Concrete
Finite element analysis of rectangular RC beams strengthened with FRP laminates under pure torsion
...Show More Authors

Scopus (20)
Crossref (16)
Scopus Clarivate Crossref
Publication Date
Mon Dec 25 2017
Journal Name
Al-khwarizmi Engineering Journal
A new Cumulative Damage Model for Fatigue Life Prediction under Shot Peening Treatment
...Show More Authors

 Abstract

In this paper, fatigue damage accumulation were studied using many methods i.e.Corton-Dalon (CD),Corton-Dalon-Marsh(CDM), new non-linear model and experimental method. The prediction of fatigue lifetimes based on the two classical methods, Corton-Dalon (CD)andCorton-Dalon-Marsh (CDM), are uneconomic and non-conservative respectively. However satisfactory predictions were obtained by applying the proposed non-linear model (present model) for medium carbon steel compared with experimental work. Many shortcomings of the two classical methods are related to their inability to take into account the surface treatment effect as shot peening. It is clear that the new model shows that a much better and cons

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 01 2019
Journal Name
Materials Science-poland
Electrical and thermal characteristics of MWCNTs modified carbon fiber/epoxy composite films
...Show More Authors
Abstract<p>To enhance interfacial bonding between carbon fibers and epoxy matrix, the carbon fibers have been modified with multiwall carbon nanotubes (MWCNTs) using the dip- coating technique. FT-IR spectrum of the MWCNTs shows a peak at 1640 cm<sup>−1</sup> corresponding to the stretching mode of the C=C double bond which forms the framework of the carbon nanotube sidewall. The broad peak at 3430 cm<sup>−1</sup> is due to O–H stretching vibration of hydroxyl groups and the peak at 1712 cm<sup>−1</sup> corresponds to the carboxylic (C=O) group attached to the carbon fiber. The peaks at 2927 cm<sup>−1</sup> and 2862 cm<sup>−1</sup> ar</p> ... Show More
View Publication
Scopus (44)
Crossref (42)
Scopus Clarivate Crossref
Publication Date
Sun Apr 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
Evidence Supports The Formation Of Isoimides Derived From Pyromellitic Dianhydride
...Show More Authors

Some new mono isoimides of asymmetrical pyromillitdiimide derived from pyromellitic dianhydride were synthesized and studied by their melting points, FTIR, and 1HNMR spectroscopy and CHN analysis (for some of them) and it was proved that the mechanism of the formation of these isoimides followed, the mechanism suggested by Cotter et al. by using N, N─-dicyclohexylcarbodiimide as dehydrating agent, in spite of the groups attached to the phenyl moiety as mentioned in literatures.

Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
THE STATIC ANALYSIS OF COMPOSITE AIRCRAFT WINGBOX STRUCTURE
...Show More Authors

In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Dec 15 2011
Journal Name
Iraqi Journal Of Laser
The Optical Limiting Behaviour of Prepared Silver Nanoparticles Embedded in Polymer Film
...Show More Authors

In the present work, silver nanoparticles were prepared. Nonlinear optical properties and
optical limiting of silver nanoparticles were investigated.Standard chemical synthesis method was used at
diffrent weight ratio(0.038, 0.058 and 0.078) of silver nitrate. Several testing were done to obtain the
characteristics of the sample. Z-Scan experiments were performed using 30 ns Q-switched Nd:YAG
laser at 1064 nm and 532 nm at different intensities. The results showed that the nonlinear refractive
index is directly proportional to the input intensities, which caused by the self-focusing of the material.
In addition, the optical limiting behavior has been studied. The results showed that the sample could be
used as an opt

... Show More
View Publication Preview PDF