Preferred Language
Articles
/
alkej-519
Investigation of Thermal Stress Distribution in Laser Spot Welding Process
...Show More Authors

The objective of this paper was to study the laser spot welding process of low carbon steel sheet. The investigations were based on analytical and finite element analyses. The analytical analysis was focused on a consistent set of equations representing interaction of the laser beam with materials. The numerical analysis based on 3-D finite element analysis of heat flow during laser spot welding taken into account the temperature dependence of the physical properties and latent heat of transformations using ANSYS code V.10.0 to simulate the laser welding process. The effect of laser operating parameters on the results of the temperature profile were studied in addition to the effect on thermal stresses  and dimensions of the laser welded workpiece which showed good correlations between analytical and numerical results. It was found that the temperature gradients during laser welding are usually very large and it was viewed that very high temperature at the center of the workpiece, and is decreased very significantly as propagating along the radial direction. Also it found that the thermal residual stresses around the laser spot due to plastic strains were very small and localized within 1.0 mm range. It is concluded that the laser welding process is effective to reduce the welding residual stress. The stresses along the lateral direction of the workpiece changed from compression at the spot under the laser beam and tension away from the spot at the end of welding to tension at the spot under the laser beam and compression away from the spot when it cooled, which are in a good agreement with the published results.

   

View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Dec 21 2023
Journal Name
Mathematical Modelling Of Engineering Problems
A Numerical Investigation into Wheel-Track Profile Optimization for Minimizing Stress and Mitigating Hunting Phenomena
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Thu Aug 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The cognitive complexity of the leaders and their impact on the organizational flexibility of field research at the company's headquarters for the distribution of petroleum products
...Show More Authors

The present research aims to test the effect of cognitive complexity as an independent variable in organizational agility as a responsive variable among the leaders working at the headquarters of the Iraqi Petroleum Products Distribution Company.

 To conclude a number of recommendations that contribute in the organizational agility in the company, and due to the importance of this research in public organizations and its notable role in community organizations. The research was carried out on a random sample of 101 individuals out of a total of 308, which represents the high leaders in the company (general managers, head of departments, and division officials). A questionnaire was used as information

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
An Investigation into Thermal Performance of Mist Water System and The Related Consumption Energy
...Show More Authors

Experimental tests were conducted to investigate the thermal performance (cooling effect) of water mist system consisting of 5μm volume median diameter droplets in reducing the heat gain entering a room through the roof and the west wall by reducing the outside surface temperature due to the evaporative cooling effect during the hot dry summer of Baghdad/Iraq. The test period
was Fifty one days during the months May, June, and July 2012. The single test day consists of 16 test hours starting from 8:00 am to 12:00 pm. The results showed a reduction range of 1.71 to 15.5℃ of the roof outside surface temperature and 21.3 to 76.6% reduction in the daily heat flux entering the room through the roof compared with the case of not using w

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Aug 31 2019
Journal Name
Iraqi Journal Of Physics
Investigation the effect of post deposition thermal treatment on properties P3HT and P3HT:PCBM blend.
...Show More Authors

  This work reports the study of heat treatment effect on the structural, morphological, optical and electrical properties of poly [3-hexylthiophene] and its blend with [6,6]-phenyl C61 butyric acid methyl ester ( P3HT:PC61BM). X-ray diffraction (XRD) measurements show that the crystallinity of the films increased with annealing. The evaluation of surface roughness and morphology was investigated using atomic force microscope (AFM), and field emission scanning microscope(FESEM). The optical properties were emphasized a strong optical absorption of P3HT compared with the blend. Hall effect measurement was used to study the electrical properties which revealed there is an increase in the electrical conductivity and Hall mobility of th

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Jul 31 2017
Journal Name
Journal Of Engineering
Experimental and Numerical Investigation of Hyper Composite Plate Structure Under Thermal and Mechanical Loadings
...Show More Authors

View Publication Preview PDF
Publication Date
Tue Mar 05 2024
Journal Name
Scientific Reports
Mesoporous Ag@WO3 core–shell, an investigation at different concentrated environment employing laser ablation in liquid
...Show More Authors
Abstract<p>In this study, silver-tungsten oxide core–shell nanoparticles (Ag–WO<sub>3</sub> NPs) were synthesized by pulsed laser ablation in liquid employing a (1.06 µm) Q-switched Nd:YAG laser, at different Ag colloidal concentration environment (different core concentration). The produced Ag–WO<sub>3</sub> core–shell NPs were subjected to characterization using UV–visible spectrophotometry, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive spectroscopy, electrical analysis, and photoluminescence PL. The UV–visible spectra exhibited distinct absorption peaks at around 200 and 405 nm, which attributed to the occurrence of surface Plasmon reson</p> ... Show More
View Publication
Scopus (20)
Crossref (23)
Scopus Clarivate Crossref
Publication Date
Sat Aug 31 2019
Journal Name
Iraqi Journal Of Physics
The Effect of Laser And Thermal Treatment on the Hardness and Adhesion Force on the Cermet Coating By Thermal Spray Technique
...Show More Authors

Ceramic coating compose from a ceramic mixture (MgO, Al2O3) and metall (Al-Ni) were produced by Thermal Spray Technique. The mixed ratio of used materials Al:Ni (50%) and 40% of Al2O3 and 10% MgO. This mixture was spray on a stainless steel substrate of type (316 L) by using thermal spray with flame method and at spraying distances (8, 12, 16 and 20) cm, then the prepared films were treated by laser and thermal treatment. After that performing a hardness and adhesion tests were eximined. The present study shows that the best value of the thermal treatment is 1000 ℃ for 30 mint; the optimum spray distance is 12 cm and most suitable laser is 500 mJ where the microscopic and mechanical character

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Feb 27 2018
Journal Name
Iraqi Journal Of Laser
Investigation of Densified SiO2 Sol-Gel Thin Films Using Conventional and DPSS Laser Techniques
...Show More Authors

The prepared nanostructure SiO2 thin films were densified by two techniques (conventional and Diode Pumped Solid State Laser (DPSS) (532 nm). X-ray diffraction (XRD), Field Emission Scanning electron microscopy (FESEM), and Atomic Force Microscope (AFM) technique were used to analyze the samples. XRD results showed that the structure of SiO2 thin films was amorphous for both Oven and Laser densification. FESEM and AFM images revealed that the shape of nano silica is spherical and the particle size is in nano range. The small particle size of SiO2 thin film densified by DPSS Laser was (26 nm) , while the smallest particle size of SiO2 thin film densified by Oven was (111 nm).

View Publication Preview PDF
Publication Date
Sun Jul 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Prevalence of Posttraumatic Stress Symptomatology and Distribution of Attachment Patterns 1 and 5 Months after a Terrorist Attack
...Show More Authors

As a consequence of a terrorist attack, people may experience posttraumatic stress disorder (PTSD) and lack of feeling secure in relationships. This longitudinal study aimed to examine the prevalence of PTSD symptoms over time, the relationship between adult attachment styles and PTSD, as well as their association with degree of exposure, and finally to consider the distribution and the trajectory of attachment styles. The sample consisted of 235 students (M=125, F=110) who were exposed to different levels of trauma intensity in response to a bombing attack. Participants were recruited and assessed approximately 1 month and 5 months after the attack using a battery of questionnaires. Findings revealed, as expected, that 79.5% of the part

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 01 2019
Journal Name
Iraqi Journal Of Agricultural Sciences
Effect of welding heat input on corrosion rate of sprinkler irrigation piping joints by tig welding used in South of Iraq
...Show More Authors

Preview PDF
Scopus (2)
Scopus