This paper presents an analytical study of the Bond stress and its
relationship with relative slip between the concrete and steel using
finite element method.
Moreover, it presents a probabilistic study using statistics theory on
the data as a re
sult from analytical study to get the bond stress-slip
relationship, which represents the bond equation.
It was investigated in this study the influence of
Carboxymethylcellolose (CMC) solution concentration,
temperature, and pH on the rheological properties according to the
shear stress as function of shear rate. Experimental results show that
shea
r stress increase at all operational conditions as the shear rate
increase. When the shear rate is constant, the shear stress increases
also with the increasing of both concentration and pH as well as the
decreasing of temperature.
3D finite elements analysis study aims to conduct a
biomechanical comparison between two cantilever’s lengths with two different
degrees of tilting the implants.
The research was conducted on some olive
varieties known as Alsourani- Aldan- Mahazm Abu Satel- Alglet-
Alnepali, in the aim of comparing their tolerance against the stress
of salinity (sodium chloride) through some morphological and
physiological traits. Different concentrations of salt as well as to
the control (fresh water) were used in this experiment.
Tensile and bending tests modeling have been undertaken for various welded joints
which were different in shape and design. Also, the hot spot stress was calculated at critical
failure areas using the finite elements analysis method. There was a go
od similarity
between experimentally defined critical areas in certain certified literature and those in our
modeling. It appeared that the information listed in the international institute for welding
(IIW) in regards of hot spot stress method gives relatively accurate values for the welded
joints possibility to endure fatigue loading and keep their desired mechanical properties
even those joints that could fail only at the connecting area with the base metal.
يُعتبر ترميم العناصر الإنشائية من الأعمال الأكثر حضوراً في عالم البناء، يعود ذلك لقصور في التنفيذ أحياناً، و للظروف القاسية التي تتعرض لها المنشآت الهندسية أحياناً أخرى. تُستخدم في عمليات الترميم و التدعيم مواد خاصة يجب أن تتصف بسرعة التصلب و المقاوم
ة و الديمومة العاليتين و جودة الالتصاق مع السطوح المعدة للترميم.
قمنا في هذا البحث بدراسة تأثير طبيعة مادة الترميم و السطح المقابل على نجاح الترميم و الذي يُعتبر إجهاد الالتصاق من أهم مؤشراته. اعتمدنا في قياس إجهاد الالتصاق على تقنية نزع مادة الترميم عن سطح محدد بتطبيق إجهاد شد مباشر عليه لاقتلاعه عن السطح (Pull Off Adhesion Testing – ASTM D4541).
تُظهر النتائج التي حصلنا عليها الأهمية القصوى لخصائص مادة الترميم و طبيعة السطح على إجهاد الالتصاق المقاس، إذ تراوحت قيم إجهاد الالتصاق على السطوح بين 0.2 و 3Mpa. و تأثرت قيم الإجهاد بعاملين رئيسيين هما مقاومة مادة الترميم المطبقة و قوامها، مع الإشارة إلى أن القوام يجب أن يترافق مع قيم جيدة للمقاومة الميكانيكية و هو ما يستدعي العمل على تحسين القوام من خلال استخدام بعض الملدنات عالية الأداء، أو الإضافات البوليميرية الخاصة كمطاط الستيرين بوتادين (styrene-butadiene rubber SBR).
Vulnerability assessment of freshwater resources in the Orontes
basin was estimated in the provinces of Homs, Hama and Idlib to
better understand the current situation of water under the prevailing
conditions and to identify the most prominent fac
tors that influence
water susceptibility to environmental changes. This study helps
decision-makers in evaluating and modify existing policies and
implementing suitable measures to improve water resource
management.
The objective of this research is to study the effect of wood ash in
rheological properties of Self – compacting mortar (SCM). By
implemented some mixtures with different percentage from wood
ash with two kinds of cement and three kinds of super plasticizer
and study the effect in slump flow and yield stress to this
mixtures.
Recently, the importance of high Strength concrete has appeared due to its
application in manufacturing most of the concrete structures and members, as well as to its
importance in the implementation of civilian facilities like bridge bases, skyscr
apers and in
implementing the columns and platforms which carry oil installations carried out in the
oceans and seas. The research aims to design concrete mixtures with cylindrical resistors
( 55- 65- 75 Mpa) according to the American code AcI-211-4R-93 by using local and
appropriate additions as well as explaining the method used in designing. Then, studying
the transformation in stress strain curve – deformation
(σ- ζ ) undergoing a simple pressure on the previous samples throughout the
available devices. Then, it was compared to the charts obtained mathematically .Law
behaviour of stress strain and deformation curve was rated, in addition to modulus of
elasticity taken from the chart.
Couple of results and recommendations related to the issue were concluded, those
which were applied in praxis.
Sandwich panels are locally produced with two faces of metal those which cover a
hard adhesive and thick core of polyurethane. The widely Extend of these panels increase
day for day as structural elements imitating the function necessities of the e
ngineering
construction.
The use of those panels as carried structural elements in wall or ceiling structures can
coincide with a submission of their sections materials, especially the two faces to the
change in a nature of the normal stress acted on them due to the alternate of the panel part
bending statically or dynamically when the alternate was produced from the change of
the loading acting direct on it or from the alternate of the live loading on the adjacent fields
of the continuous systems from it.
The evaluation of the sustain capacity and stability of the sandwich elements
consisted of such panels performs depended to the critical stress value leaded to arise of the
wrinkling waves of the compressive face of the panel that it values depended first on the
quality and properties of the production.
The research handled the testing of the sustainability and stability of the local
produced sandwich panel due to the alternate in a nature of it stress statically as a carried
structural element in the structural system built from such panels.
The conclusions of the research showed that this produced panel
follows a linear behavior too even in the case of the change of its bending direction or stress
nature of its face, especially in the loading steps coincided at least to the arising of the critical
wrinkling stress, whereas the value of this stress decreases 40% from its value for the
loading or bending case of the panel in only one direction.
