Engineering and Technology Journal

Avoiding collisions is an important matter in the majority of transport systems and in many other applications in driverless cars it is very important to have an active collision avoidance system since only the car to take an action and no driver to help. The goals of collision avoidance systems are tracking objects of possible collision risks and decide any action to avoid or mitigate a collision with the help of sensors and radars. Car accidents have become quite common nowadays. After investigations, conclusions have stated that a great deal of those accidents happened because drivers fail to stop the car at the right time. Sometimes, the pedestrians are not crossing the road at the right time. Researchers discovered that about 35 percent of people die due to accidents, 98 percent of which die because of fatal road accidents. Many car industries have proposed an AI system in the vehicles for the aim of reducing accidents and this is considered as the backbone of the auto-driven car. However, this system is complex and expansive. That is why; ordinary people are still under the risk of accidents . The system proposed to driverless cars is simulated and modeled via small Miniatures and in Matlab and assembled in Arduino.

The current work includes the dynamic structural analysis of wire rope with different helix angle. The main objectives are; estimating the stress and deflection for each helix angle, comparing the results to get the best helix angle suitable for practical applications. This paper falls into two parts: The first part includes modal analysis for the models of wire rope using finite element method with certain boundary conditions that are suitable to obtain the first five frequencies for each helix angle and the second part focuses on harmonic analysis of wire rope to estimate stress and deflection and compares maximum results that coincide with the first natural frequency of each model. In the analysis the results of each helix angle were compared to other helix angle results, the structure of 82° helix angle have the smallest stresses and deflection. That means when the helix angle increases the flexibility decrease and rigidity increase.

This research covers the use of cellular lightweight concrete waste as recycled coarse aggregates to produce lightweight concrete. Various volume fractions of coarse aggregate (35%, 50%, and 75%) were used. The specimens were tested for compressive strength and density at age of 28-days. The compressive strengths for the resulting lightweight concrete with a density of (2131, 1826 and 1630) kg/m3 were (24, 22.6 and 11.5) MPa, respectively. In addition, silica fume was utilized as a constant replacement ratio 6% of cement weight for mixes lightweight aggregate to enhance the compressive strength of such concrete.

A tool path generation algorithm has been proposed and implemented in the presented work. The aim of the development of tool path algorithm is to machine parametric surface with a given tolerance and scallop height. The algorithm proposes dividing the desired parametric surface to several linear segments depending on the desired accuracy of the parametric surface. The B-spline technique has been used to generate the required data of the parametric surface. After generating the tool path, the cutter movement has been simulated allowing to reduce the cutting time and cost. The tool path is verified on the C-TEK CNC milling machine by machining six models. Various tool path strategies are also discussed and compared with the developed algorithm. The machining performance includes machining time; dimensional accuracy and surface roughness were measured for result evaluation. A measuring method has been proposed and implemented to measure the accuracy of the final 3D models. A Digital 3D-Touch Probe was used. The statistical method of error assessment and similarity factor has been implemented in this work to show the efficiency of the proposed works. The results showed that the similarity factor of the proposed works were (87.6%) for one model, and (85.9%), (89.6%) for other models. Matlab (v.7.1), UG-NX8.5, and VERCUT software have been used in this work for implementation. A comparison between the proposed method and UG-NX8 has been done to present the flexibility of the proposed method.

The present work presents an investigation the effect of adding various fiber materials such as (glass, nylon, and carbon) into the concrete mix for inspecting and compare the mechanical properties of different fibers reinforced concrete. Two different fiber length states of (short=3cm and long=10cm) are used in this work. The concrete of ordinary Portland cement of (1:1.5:3), (cement: sand: gravel), were mixed with each of the fiber materials at four different weight percentages (0, 0.4, 0.8, and 1.2) wt% per cement content. Compressive strength and flexural strength were experimentally investigated of different fibers reinforced concrete specimens after curing for 28 days. The results showed that the incorporation of various fibers with the concrete mix generally improved the strength of concrete by improving the toughness. The flexural strength of concrete with addition of various fibers was strongly enhanced than compression. Addition 0.8% of nylon fiber to concrete resulted in the maximum increase of its compressive strength, reaching the rate of increasing to 11.08% for short fiber and 20.75% for long fiber. Addition 1.2% of nylon fiber to concrete mix resulted in the maximum increase of the flexural strength, reaching rate of increasing to 120.02% for short fiber and 211.49% for long fiber. Increasing the length of fibers increases the strength of the concrete but a little extent. Among these fibers, nylon containing concrete composite exhibits promising mechanical strength that could be easily used as low-cost partitioning wall, false ceiling, and other household purposes.