At the start of welding activities in oil and gas projects, high welding rejection rates (WRR) are often reported. This is a cause for concern to companies because welding defects that are not identified nor corrected can have serious consequences, such as on asset integrity, cost of rework, and schedule impact. Therefore, the quality organizations immediately investigate the different causes and recommend solutions which eventually contributes toward lowering the WRR. Based on recent field studies conducted in oil and gas projects using the Six Sigma methodology, high WRRs are caused by many factors, including but not limited to the following: 1. New and inexperienced welders with poor welding techniques. 2. Poor environments surrounding the welding activities. 3. Discrepancies and inaccurate data in the welding tracking system (WTS). These contributing factors can be reduced and eliminated by implementing a strong welding inspection and control program with the following recommendations: 1. Screen for qualified and experienced welders with a proven successful welding history before starting the welding. 2. Test the welders on-site before actual production welding. 3. Implement an encouragement scheme for welders by having frequent toolbox meetings and presenting awards for the best welders according to the lowest rejection rates. 4. Assess the WTS constantly to prevent any inaccurate data.

In this paper, we present a framework to define, visualise, analyse and manage a design factory in a complex engineering environment. Design engineering is the core of product development and provides high leverage in cost, quality and time to market. Lean principles can be applied to gain these improvements to the design management system. However, unlike manufacturing and operations, design processes are inherently non-linear and iterative in nature. In addition, design outputs, queues and work in progress are not visible and tangible. This creates challenges in applying lean principles in the design environment. To alleviate these issues design engineering is treated as a factory and its key steps are mapped by using the gated review process. The inputs and outputs of the design factory system are identified and employed to create an effective productivity improvement dashboard. The gated review process steps are used to understand the flow of design solutions. Lean principles and structured root-cause analysis is used to create a system to visualise, analyse and manage the design factory.

In this paper, a framework based on Augmented Reality (AR) and a mobile device is proposed for monitoring mechanical components during fatigue tests. This solution enables the user to move around and to inspect the component through AR from different points of view. In addition, the framework proposes a solution to estimate in real time the crack growth and to visualize it directly onto the component. A user application is developed according to the proposed framework and it is used for case studies of fatigue test for adhesively bonded joints.

The focus of this paper is on the development of a high-fidelity electro-mechanical Control Loading System (CLS) for a rotary wing aircraft simulator. CLS is one of the major components of a flight simulator. It is used for providing realistic force feedback to pilots. The pilot in a real aircraft feels the forces acting on control surfaces through cockpit controls. During simulation, these forces are produced by CLS actuators. For this reason, CLS must behave exactly like the aircraft control hardware, statically and dynamically. The fidelity of the force feel simulation is a key criterion for flight simulation certification. It is also important that a CLS design is reconfigurable and modular such that it conforms easily to different simulator models and simulations of different aircrafts. The work also includes system integration of a research simulator for testing purposes. Design and selection of hardware and software components of the CLS and the simulator are presented along with the overall system architecture.

This work focuses on the development of a methodology for the complete reconstruction of the 3D geometry of a concrete bridge. 3D scanning technology was selected as the most apt to the task as it provides very detailed geometrical informations. A dedicated carriage system for a compact and lightweight laser scanner has been designed and built as a first prototype to be used on laboratory as well as future on-field tests. A first assessment of the design constraints has been carried out, based on the general goal of implementing a system able to be used with existing inspection vehicles with minimal modifications. The specific electronic system for management and control of the carriage system and the management of the associated tracking system has been also designed and realized. Some preliminary tests have been performed at Politecnico di Milano University campus to assess the viability and analyze the performance of the early design choices.

This paper investigates the kinematical behavior of a polymer based star-shaped actuator, able to produce mechanical work through the shape memory effect, that allows a significant shape variations on the application of an external stimulus. The adopted material is a semicrystalline network based on poly(ε-caprolactone) crosslinked by thermal curing; the material was adopted due to its fast recovery process when heated close to the melting temperature and the high recovery degree, and, due to its good biocompatibility, it may suitable for biomedical application. The original, or “permanent”, material shape is that of a cylindrical annulus, which is set in a “temporary” configuration as a six spikes star. The temporary shape is fixed through a thermo-mechanical program, involving deformation above melting temperature and cooling under fixed strain and carried out by means of an ad-hoc designed fixture. By heating the deformed specimen above the melting temperature, the system is able to recover the original cylindrical shape realizing a motion and a mechanical power. This peculiar response, consisting in a progressive radial expansion activated by temperature, may be considered for application as self-expanding stenting device triggered by the human body temperature. The shape of the system, that changes during the transformation, can be described as a two dimensional temporal function that represents the mean line of the section of the cylindrical annulus (perpendicular to the height of the annulus). This temporal function is a combination of a circular function and of a modified rhodoneal function and, after a proper calibration through experimental tests, is used to evaluate the kinematics of the system. The function is able to describe adequately the shape evolution experimentally displayed by the samples, with a very good agreement at the starting and final instants of the transformation, while the accuracy during the transformation is acceptable for the proposed application.

The basics of antifriction coatings is to lower the frictional response of a surface. The coated material should either lower the interfacial shearing or increase stiffness of the surface. The latter should be reached by using carbon nano-fillers embedded in a polymer matrix. We choose PMMA as a matrix. The objective of this study is to gain knowledge on the influence of carbon nano-fillers on the surface response of PMMA nano-composites.

In this paper, fully developed flow of a couple-stress fluid between two long vertical walls in presence of viscous dissipation and radiative heat flux with heat and mass transfer is considered. Temperature and concentration fields at one of the walls are oscillating around a non-zero value. The coupled equations governing the problem are discretized using Differential Quadrature Method, and solved using Newton-Raphson Method and Evolutionary Algorithm hybrid scheme. The expressions for velocity, temperature, and concentration fields for fully developed unsteady flow are obtained.

As the energy landscape changes globally with the development of tight oil and gas resources, questions about the rail safety and tighter regulations around safety and environment, energy insiders are asking the question; are pipelines still the safest way to transport energy? In a recent study conducted by T.D. Williamson (TDW) (1) this paper uncovers some current industry trends, drivers and restraints that will shape the pipelines landscape for the future. The study looked at regional trends, technology applications and future project developments in the pipelines arena and how this is influencing how pipelines are being designed, installed and utilized. The study identified that there were four distinct pipeline “themes” over the pipeline life cycle, which comprise: • Infrastructure – pipeline new build for growth, replacement and expansion, • Integrity Management – management of the integrity for new and existing pipelines, • Flow Assurance & Throughput – optimizing throughput and uptime for new and existing pipelines, • Management of Human Capital – acquiring, developing and retaining competent people or outsourcing. The paper will discuss how these needs imbedded in these themes are met or, as in some cases, unmet. The paper also looks at developments in materials for new pipelines, pipeline monitoring and leak detection (from cables to dogs to, unmanned vehicles), newer products that are being shipped (from higher hydrogen content methane gas to carbon dioxide from capture schemes to diluted bitumen from the oil sands), the impact of “big data” (from Mb to Yb), and how operators are looking to manage emergencies (from spill response to emergency planning and operational readiness). This paper will compare safety records for energy transportation as well as the new demands being put on energy companies that will propose an answer to the question posed in the title.

During the year, due to weather conditions, the temperature fluctuations at surface level cause problems in underground pipes as a result of freezing water. One of the best prevention strategies is the use of polyurethane floor insulation for keeping the temperature of clay above zero degrees Celsius. In this study to calculate the minimum thickness of polyurethane insulation layer, the differential equation of energy is solved based on principle of separation of variables using imaginary eigenvalues for consistency with the temperature distribution in multi-layer consist of asphalt, gravel and polyurethane with finite thickness and clay as a semi-infinite medium with periodic thermal boundary conditions at surface level. Numerical approach is performed in Matlab and the results show that by using a thin layer of polyurethane it’s possible to greatly reduce the insertion depth of water pipes.

The objectives in this paper are to investigate the effects of the filler content and size on the effective thermal conductivity of the PE/Al; PE/Cu, PE/Fe and PE/bronze composites. The polymer matrix of the polymer/metal composites was two types of polyethylenes: LDPE and HDPE (from Basell Orlen). The following polymer/metal composites obtained by extrusion process containing: 10% by weight of Al, Cu, Fe and bronze powder in LDPE matrix and composites containing 5, 10, 15 and 20% by weight of Al flakes in HDPE polymer were prepared and tested. Adding in the extrusion process 10% by weight of bronze powder into the polyethylene, increased more than five times the thermal diffusivity of produced composite. Use as a filler 20% wt. of aluminum flake increases it by more than twice. The study showed the ability to produce polyethylene matrix composites with the addition of metal powder fillers (Al, Cu, Fe, and bronze). Analyzing the measuring results of thermal diffusivity coefficient by Angstrom method, it can be concluded that with the appropriate filler content, the particles are located close enough to each other to form a continuous conductive path, then the thermal diffusivity of the composite increases significantly.

Concrete bridge inspection is nowadays primarily a slow, subjective, non-comprehensive and costly set of procedures. Automation of the acquisition method is especially desirable for economical and repeatability reasons. Digital data is normally derived from well established non-destructive testing techniques, high resolution cameras and, more recently, by 3D laser scanning. This latter technique has some advantageous aspects in terms of reliability, repeatability, completeness and intuitiveness of the analysis of the resulting 3D reconstruction of the concrete structure. Statical laser scanning is, though, impractical for a variety of different reasons. A possible way of overcoming such difficulties is represented by dynamical measurement, achieved by moving in a prescribed manner the laser scanner during the scanning process. This procedure, on the other hand, requires a reliable tracking system for the laser scanner position and orientation. This work focuses on the development of such system, based primarily on computer vision measurement systems. A compact and lightweight 3D laser scanner has been placed on an automated carrier able to move along a standard inspection by-bridge, and a system of cameras and transducers has been designed to measure the carrier position and orientation based on the assumption of rigid body motion of the by-bridge multi-link arm during inspection operations. Several experimental tests have been performed to assess the viability of the proposed system and to evaluate its performance.

Sensor nodes are innovative devices that can perform measurements on a large scale and communicate over a network. One of the most significant problems regarding the sensor nodes is how to supply power to a large number of devices. For this reason, they greatly benefit from energy harvesting techniques which can provide energy recovered directly from the environment. A study of the design and the modeling of an autonomous sensor node, powered by a vibrational piezoelectric harvester, is reported here. Subject of the first part of the analysis is a piezoelectric bimorph: an analytical model is proposed in order to estimate the performance, giving particular attention to the optimal mechanical and electrical parameters. The model is then validated through experimental tests, assuming different kinds of real scenarios. Then the results are used to design a device that can benefit from this harvester. In particular a wireless sensor node is developed, for which the energy scavenging ensures energy autonomy and long-term operability. Thanks to a particular harvesting circuit and opportune algorithms for energy management, this system is able to extract energy from vibrations and store it into capacitors. The embedded accelerometer and a wireless module make this device ideal for Structure Health Monitoring purposes.

The repeated failure of Agitator in the Phosphoric acid Reactor in MPC was a major incident causing high downtime and production loss. While doing the root cause analysis of this “Class A” incident many causes not considered in normal agitator design were considered and analyzed. This paper lists such special cases and the proposed solutions and calculations to be incorporated in design of critical systems with varying process fluid parameters for different applications. Agitators constitute almost 20% of rotating equipment in a fertilizer and similar plants but are given less priority compared to others until a severe failure happens. There are no standard analytical design criteria for agitator design due to large variations and uncertainties in the process conditions in the reactor or tank. Most designs are left to the EPC companies using preformatted design models based on experimental results, on the combination of few variables. (Like Power Number, Pumping Number, Geometrical ratios etc.) However, none these models considers the fluid flow conditions which changes inside the reactor which affects the agitator design in many ways like Localized flow, non-homogenous fluid, solid contents, Liquid additives or recycling etc. which can cause much higher alternating forces and bending stresses at the joints holding the blades causing fatigue and other failures. This paper gives more quantitative design calculations to determine the forces acting on the agitator and blades as listed above which can be used in similar application even with different fluids.

Using rather well known theory about capillary bridges between two electrodes we calculate the tensile force that can be applied to liquid metal contacts in the micrometer regime. Assuming circular symmetry, full wetting of the electrodes, and neglecting gravity, we present a brief review of the necessary theory and find numerically the forces to be in the 100 μN range for liquid metals as mercury and liquid Gallium suspended between electrodes of 20 μm radius.

The paper proposes a brief overview of the commonly adopted approaches for the experimental study of scuffing on gears for advanced applications and suggests a new methodology for the design of an experimental campaign aimed at determining the scuffing resistance of an innovative aerospace gear material. The present study has been carried out by AM Testing srl in collaboration with Avio Aero within the VHLGM ( Validation of High Load Capacity Gear Material ) project of the Clean Sky Sustainable and Green Engines framework.

In this paper, an optimal control strategy (i.e., offset settings system) based on the new Multi-objective Particle Swarm Optimization with Differential Evolution (MOPSO-DE) technique is developed and presented. The MOPSO-DE algorithm is used for calculating the optimal positions (i.e., offset settings) for the cutting tools in lathe machines. This optimal control strategy yields interesting results without a need to go through the complex mathematical modeling of the lathe system. The proposed technique is validated considering a real-world industrial system. This strategy is designed to take an action every 20 pieces, and it takes only 2.5 sec to run the code and optimally calculate the new settings. The control strategy is implemented using two high precision linear stepper motors. By implementing the new optimal control strategy, the estimated number of the defective pieces per day can be reduced by 85%.

In this study, we adopt a dual power system for extension (DPES) operation by combining the existing power system of an electric vehicle with a hydrogen fuel cell. This was to enhance the durability of the electric vehicle and reduce the inconvenience of battery charging. The lithium battery acts as the primary power source and has real-time monitoring of its state of charge (SOC), while the hydrogen fuel cells act as the auxiliary power supply. The auxiliary power can be used either directly or for charging the lithium battery while the vehicle is in its idle state. The dual power system is coupled with a dual-mode motor controller and energy management system. This study aims to apply the dual power system on the electric vehicle using hydrogen fuel cells. We designed a simulation platform for real driving conditions using Labview to send and receive control commands. In this study, we simulated the road cycles of the Economic Commission for Europe (ECE-40), Japanese legislative cycle (JP10) and the World-wide Motorcycle Emissions Test Cycle (WMTC), using Proportional-integral Control (PI) for automatic tracking and employing engineering error analysis to determine the most suitable PI parameter values for the simulated system. The results showed that using a fixed 100 W fuel cell could enhance the operation time up to 21 %, 21 %, and 14 % for the road cycles of the ECE-40, JP10, and WMTC, respectively. Due to the required features of an actual vehicle, we also designed an energy limiting system to manage the driver-controlled electronic throttle by controlling the instantaneous and maximum power output of the motor in order to achieve savings in energy consumption, increase its operation time, protect the system, and enhance its durability.

Compared to a conventional vapor compression refrigeration system, a magnetocaloric refrigerator has many advantages, such as potentially high efficiency, low vibration and avoidance of refrigerants that deplete the ozone layer and cause the greenhouse effect. As a main component of the active magnetic regenerative refrigerator, the regenerator plays an important role in the cooling performance and efficiency of the whole system. However, the regenerator design is constrained by several external factors, such as the geometry of the magnetic field source and flow resistance. In this work, novel regenerators with complex flow arrangements, providing high performance at lower pressure drop, are investigated. Correspondingly a one dimensional model is presented and comparative studies between novel and conventional regenerators are carried out by simulation. The effect of regenerator geometries and different flow arrangements on the cooling performance, pressure drop and efficiency are investigated. In particular, the effect of so-called dead volume on the performance of a regenerator is researched.

Evaporative condensers operate at lower temperatures and with a higher efficiency compared to air condensers, as heat rejection is limited by air wet bulb temperature and mainly caused by water vaporization. This reduces the compressor pressure-lift and improves refrigeration cycle performance. Due to complex phenomena of heat and mass transfer on the tube bundles, modeling the evaporative condensers is a hard task and fine grids in numerical simulations are requested to reach acceptable results. A two-dimensional steady state numerical model at the single tube scale has been developed in Ansys-Fluent (release- 14.5), adopting the VOF multiphase model. Moist air has been treated as a mixture of air and water vapor species, while water vaporization and latent heat have been modeled with a C++ User Defined Function. The tube wall temperature has been assumed constant. The aim of this work is to describe the developed numerical model and to validate it by comparing results obtained at different operating conditions with empirical relationships found in the literature in terms of combined and overall heat transfer coefficients. Combined heat transfer coefficient variation along the tube surface has been analyzed, observing that the heat transfer coefficient is higher in the impingement zone, becomes approximately uniform and rises approaching the trailing edge. Moisture content distributions at different sections through the heat exchanger have been examined in detail as well. This study will be the basis to investigate the performance of the whole condenser taking into account the real evolution of the operating conditions of each single tube in the bundle, whatever its arrangement.