Ali Ammouri

Lebanese American University | LAU · Department of Industrial and Mechanical Engineering

In order to meet increasingly demanding environmental regulations, redesigning mass-manufactured products for sustainable reuse is of great interest. A good percentage of the estimated world daily production of billion or so single-use Polyethylenterephtalate (PET) bottles does not get recycled. Therefore, the availability of such a bottle to meet...

From energy and CO2 footprint perspectives, this study focuses on the Life Cycle Analysis (LCA) of AA alkaline batteries considering options other than landfill namely downcycling or, more ambitiously, recycling/remanufacturing. With the exception of lead-acid batteries that are recycled intensively in an energy-efficient manner, many types of batt...

According to the Plastics Pipe Institute, butt fusion is the most widely used method for joining lengths of PE pipe and pipe to PE fittings “by heat fusion” (https://plasticpipe.org/pdf/chapter09.pdf). However, butt-welding is not energy-cognizant from the point of view of a phase-change fabrication method. This is because the source of heating is...

Friction stir processing (FSP), an offshoot from friction stir welding (FSW), is an intricate operation that involves refining the material by a rotating tool. Active control of the resulting size and distribution uniformity of grain structure is desirable. Achieving such a control across the processed area requires real-time control of the process...

An experimentally verified finite element model was used to estimate the strain rate and the temperature values which were, consequently, used in calculating the Zener–Hollomon parameter, Z-parameter, of twin-roll-cast (TRC) AZ31B after being refined by FSP (using range of spindle speeds of 600–2000 rpm and tool feed rates ranging from 75 to 900 mm...

The effects of in-process cryogenic LN cooling on the resulting grain size of the friction stir processing (FSP) of twin roll cast (TRC) magnesium alloy AZ31B. Sheets (3 mm-thick) of TRC AZ31B were friction stir processed using a wide range of processing parameters (mostly tool feed and spindle speed). The tool rotational speed was varied between 6...

In-process cryogenic cooling has been credited with more precise products and enhanced integrity of machined surfaces. Enhanced surface integrity properties include smoother and more precise surfaces, grain refinement, and increase in surface hardness. This paper reports on the effect of liquid nitrogen (LN) cryogenic cooling and cutting parameters...

In order to select the optimum parameters for friction stir welding of twin-roll cast (TRC) AZ31B Mg-Al-Cu alloy, mechanical and microstructural characterizations are performed on friction stir welded 3 mm thick sheets under different processing parameters of rotational spindle speed and feed rate. Used was a tool made from high resistance Sverker...

In-process cryogenic cooling in fabrication processes is known to — among other benefits — extend tool life and improve the surface properties of a work-piece. To provide flexible applications of cryogenic cooling, control of the cooling fluid is required. The commercial availability of such a control system is limited and, if available, is rather...

This manuscript aims to investigate the effect of cryogenic in-process cooling via liquid nitrogen on the outcomes of the friction stir processing (FSP) of twin roll cast (TRC) magnesium alloy AZ31B. Friction stir processing was performed on 3mm thick sheets of TRC AZ31B at a wide range of processing parameters. The tool rotational speed was varied...

Proper numerical modeling of the Friction Stir Processes (FSPs) requires the identification of a suitable constitutive equation which accurately describes the stress-strain material behavior under an applicable range of strains, strain rates, and temperatures. While some such equations may be perfectly suitable to simulate processes characterized b...

Utilizing a proper material model for describing the mechanical behavior of any material is key for a successful simulation of friction stir processing (FSP) where temperature, strain, and strain rate gradients vary abruptly within, and when moving away, from the stirring zone. This work presents a comparison of how faithfully do three different co...

Presented in this work is a novel tool-condition criterion dubbed as the current rise criterion (CRC). This criterion is based on the measured current values of the machine tool’s spindle and drive motors. The CRC comprises two components: (1) the current rise index (CRI) and (2) a sensitivity factor (SF) indicated as a subscript to the CRI. Curren...

An experimentally verified finite element model was used to estimate the strain rate and the temperature values which were, consequently, used in calculating the Zener–Hollomon parameter, Z-parameter, of twin-roll-cast (TRC) AZ31B after being refined by FSP (using range of spindle speeds of 600–2000 rpm and tool feed rates ranging from 75 to 900 mm...

Introduced in this work are correlations that capture the behavior of thrust force and torque vs. input process parameters in friction stir processing (FSP) of twin-roll cast (TRC) AZ3 IB. The correlations are based on the findings of an experimentally validated robust 3D FE model that was used to simulate the FSP process at different values of too...

Microstructural modification via dynamic recrystallization (DRX) is the main mechanism involved in grain refinement associated with friction stir processing. Introduced in this work is a methodology for controlling grain size through the manipulation of process parameters in friction stir processes, FSP. The methodology was demonstrated on FSP usin...

Grain size determines to a large degree the mechanical properties of the friction stir processed (FSP) material. Developed in this work is a numerical (FEM) based-model for predicting values of the Zener-Hollomon parameter (Z-parameter) as function of input process parameters during friction stir processing of AZ31B. Prediction of Z values is desir...

Controlling the temperature in friction stir processing (FSP) of Magnesium alloy AZ31b is crucial given its low melting point and surface deformability. A numerical FEM study is presented in this paper where a thermo-mechanical-based model is used for optimizing the process parameters, including active in-process cooling, in FSP. This model is simu...

Numerical simulations of the friction stir welding of dissimilar metal joints is a daunting task given the complex issues involved such as the flow mixing action and the phase transformations. In this work, a 3D thermo-mechanical FE model is developed to simulate the dissimilar friction stir welding (DFSW) of aluminum-magnesium bi-metallic joints....

This paper presents a novel actuator design for vibration-induced micromachining. The bi-directional ultrasonic elliptical vibration actuator (BUEVA) possesses a combination of features that renders it suitable for the machining a wide range of materials over a variety of cutting parameters. The cutting motion is an elliptical tool motion that rese...

The goal of a number of many recent studies is to assess the potential of cryogenic cooling in improving the sustainability of manufacturing processes. One prime interest is the enhancement of surface integrity properties of newly machined surfaces. In this paper, we study the effect of liquid nitrogen cryogenic cooling on the surface integrity of...

Introduced in this work is a relation that captures the behavior of grain size with the varying process parameters in friction stir processing of AZ31B. The relation was based on the results of a 3D FE model that was used to run simulations of the process at different tool rotational and traverse speeds. The model was validated by comparing its sta...

We assess the effects of stretch rate on the mechanical properties of Prolene® (Ethicon, Gynecare, Somerville, NJ, USA), a knitted polypropylene mesh. Prolene® , consisting of macroporous knitted polypropylene, is considered here as a suitable proxy to midurethral tape (MUT) as well as to many other prosthesis products used in surgery applications....

Friction stir welding (FSW) is a proven solid-state technique for joining metal alloys. Given the low melting temperatures of light alloys, excessive heat build-up in such joints may have undesirable consequences such as melting and/or undesired grain growth. It is widely recognized that the resulting mechanical properties of a welded joint depends...

Carbon footprint is commonly defined as the total amount of greenhouse gases produced directly or indirectly as a result of an activity. The term carbon footprint has become the standard for measuring the environmental impact of activities in several sectors (e.g., transportation, energy, construction). While there have been several studies documen...

Introduction and hypothesis Uniaxial tensile testing is commonly used to calculate values of mechanical properties of urogynecological prostheses used in stress urinary incontinence and pelvic organ prolapse surgery in women. Clinical behavior of these products has been linked to their mechanical properties, hence influencing the clinician’s prefer...

In previously published research (10, 11, 14 and 12) the authors developed a framework for analyzing the technical profiles of novice computer-aided design (CAD) trainees as they set to start training in a formal setting. The research included conducting a questionnaire to establish the trainees’ CAD-relevant technical foundation which served as th...

This paper utilizes Artificial Neural Networks (ANN) to forecast the mechanical CAD performance of novice trainees involved in formal training. We utilize 3 Artificial Neural Networks, ANN, techniques: Feed-Forward Backpropagation, Elman Backpropagation, and Generalized Regression. We also compare their predictive capabilities compared to those of...

A carbon footprint is defined as ‘The total set of greenhouse gas emissions caused directly and indirectly by an individual, event, organization or product expressed as mainly CO2 emissions [1]. Carbon footprints and their calculations have recently drawn considerable attention in order to limit Greenhouse Gas Emissions. Several carbon footprint ca...

To avoid damage to work and/or machine, real-time tool condition monitoring is necessary in automatic and sustainable manufacturing operations. In particular, metal machining with NC machine tools can benefit handsomely from the identification of dull tools in real-time so that they can be replaced. This requirement is especially true in dry (susta...

Quantitative polar maps of tool-wear of cutting tools (here, chisel drills) undergoing dry machining are charted based only on transducers reporting electrical current measurements from machine (spindle and feed drives) motors. Associated with these maps are qualitative descriptions of the various modes of tool-wear afflicting the drill tools. Thes...

To avoid damage to work and/or machine, real-time tool condition monitoring is necessary in automatic and sustainable manufacturing operations. In particular, metal machining with NC machine tools can benefit handsomely from the identification of dull tools in real-time so that they can be replaced. This requirement is especially true in dry (susta...

Compose-it is a Windows based application developed using the National Instruments LabVIEW [1] software. When compared to classical educational analysis software (e.g. PROMAL [2]), Compose-it provides several advantages including (1) user-friendly interface and (2) intelligent design features (based on the simulated annealing optimization technique...

Typically, fly cutters perform surfacing operations using small depths of cut. Due to issues relating to their salient features and geometry, and peculiar mounting, the cutting action with such cutters may cause dramatic tool wear and, often, catastrophic tool breakage. Therefore, the study of tool wear of fly cutters is of interest to the machinin...

The dimensional tolerancing knowledge management system presented in this paper uses Nested Ripple down Rules (NRDR) targeted towards incrementally capturing expert design knowledge. A demonstrated example of such captured knowledge is that which human designers utilize in order to specify dimensional tolerances on shafts and mating holes in order...

A coherent artificial neural network, ANN, software program capable of real time analysis and decision-making is utilized in this work for the automatic detection and diagnostics of tool wear during a surfacing milling operation using a fly cutter. Several sensors were utilized to collect data indirectly related to wear: current measurements from t...

Presented is the detailed design and implementation of a bi-directional ultrasonic elliptical vibration actuator (BUEVA) for micro machining. Removal of material occurs via a generated elliptical tool motion resembling a natural ‘spoon feeding’ action in contrast to in-plane, horizontal motion utilized by most existing setups. The motion is generat...