Alain Desrochers

Université de Sherbrooke | UdeS · Department of Mechanical Engineering

The main objective of this paper is to study the effect of the key parameters on the mechanical strength of adhesively bonded Al 5052-H36 joints. The key parameters are adhesive type, curing temperatureCuring temperature, and geometrical parameters. To evaluate the effect of these parameters on the performance of bonded joints, single lap joints (S...

This study investigates the fatigue behaviour of overlap laser-welded 1.6 mm thick AA5052-H36 sheets. The oscillation beam laser welding in continuous mode is adopted for preparing defect-free weld seams. Three different stitch-weld orientations (transversal, longitudinal, and diagonal with respect to the load direction, denoted in the present work...

In this study, the laser welding process is used to join 1.6-mm-thick AA5052-H36 sheets in an overlap joint configuration. Both pulse and oscillation laser beam welding were investigated for the first laser pass. Oscillation beam laser welding in continuous-wave mode show more stable and sound weld with no porosity defects compare to pulse wave (PW...

Knowledge of frame loads at the limits of the intended driving conditions is important during the design process of a vehicle structure. Yet, retrieving these loads is not trivial as the load path between the road and the frame mounting point is complex. Fortunately, recent studies have shown that multibody dynamic (MBD) simulations could be a powe...

Knowledge of frame loads at the limits of the intended driving conditions is important during the design process of a vehicle structure. Yet, retrieving these loads is not trivial as the load path between the road and the frame mounting point is complex. Fortunately, recent studies have shown that multibody dynamic (MBD) simulations could be a powe...

The design of a vehicle frame is largely dependent on the loads applied on the suspension and heavy parts mounting points. These loads can either be estimated through full analytical multibody dynamic simulations, or from semi-analytical simulations in which tire and road sub-models are not included and external vehicle loads, recorded during field...

Prediction of vehicle frame loads in both normal and extreme operating conditions is essential to accelerate the design process. Nevertheless, the loads imposed to the frame are influenced by the frame design itself as its rigidity and geometry affect the load distribution. Traditionally, frame loads are calculated from hub loads that are obtained...

In order to help the students of the Faculty of Engineering at the Université de Sherbrooke within the field of product design in engineering, the Laboratory for the Characterization and the Validation of Prototypes (LCVP) has been created. The facilities feature most of the resources needed to conduct experiments toward the estimation and measurem...

In order to help the students of the Faculty of Engineering at the Université de Sherbrooke within the field of product design in engineering, the Laboratory for the Characterization and the Validation of Prototypes (LCVP) has been created. The facilities feature most of the resources needed to conduct experiments toward the estimation and measurem...

Hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) need an energy management system (EMS) to ensure good fuel economy while maintaining battery state-of-charge (SOC) within a safe range. The EMS is in charge of the power split decision between the engine and the electrical motor. For a PHEV, the optimal power split scenario wil...

The purpose of this paper is to propose a vibro-acoustic modeling of a snowmobile suspension in order to determine the elements and transfer paths that contribute most to the global noise of this mechanical system. Two approaches, Transfer Path Analysis (TPA) and Operational Transfer Path Analysis (OTPA) are compared. The first one consists in usin...

A new method for processing and analyzing noise data from a snowmobile on a test bench is proposed and applied to compare the sound levels of two different CVT models. Because of the important dependency of the noise to the engine speed, the signal is analyzed through a relatively simple algorithm so as to be automatically associated to the engine...

The dual power source of a plug-in hybrid electric vehicle (PHEV) requires a high level control strategy in order to establish a power split decision that will minimize fuel consumption while taking full advantage of the embedded source of electrical energy. Literature shows that the optimal control of the power split is greatly influenced by the f...

This paper presents a possible scheme to integrate a SuperCapacitor pack in a full electric, battery powered, three-wheel vehicle. The proposed hybridization is built upon a fully-active parallel topology. First, a complete model based on energetic macroscopic representation is established for power energy analysis of standard driving cycles. There...

The paradox that exists between the necessity of testing physical prototypes to achieve as much design criteria as possible and the desire to minimize the number of iterations at the experimental validation stage to manage development time and cost, has led the authors to develop a detailed design methodology that guides the engineers and designers...

La présente étude porte sur la simulation numérique du transfert thermique stationnaire du pot d’échappement d’un tricycle hybride. Elle se base sur une analyse thermique du pot d’échappement afin d’optimiser le confort thermique et l’aérodynamique interne d’un tricycle hybride. La simulation sous STAR-CCM+_v7 est résolue par la méthode des volumes...

The growing interest in reducing fuel consumption and gas emissions provides an incentive for the automotive industry to innovate in the field of hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV). The two embedded power sources in these vehicles require an intelligent controller in order to make the best decision on the pow...

Virtually mounting nonrigid parts onto their fixture is proposed by researchers to remove the need for the use of complex physical inspection fixtures during the measurement process. Current approaches necessitate the pre-processing of the free-state nonrigid part’s point cloud into a suitable finite element (FE) mesh and are limited by the use of...

To reach the goal of continuous improvement on automotive vehicles, their overall design strategy needs to be reconsidered. Hence, the future design will have to use global approaches like those developed in the aerospace industry where optimization of all interacting fields is performed jointly. This strategy has been applied to the development an...

Using finite element analysis (FEA) to numerically mount compliant components onto their inspection fixture is an approach proposed by researchers in the field of computational metrology. To address the shortcomings of the underlying principle of current methods, this paper presents a boundary displacement constrained optimization using FEA. The op...

This paper deals with a computational fluid dynamics (CFD) and experimental drag analysis on an isolated rotating wheel subsystem (including its accessories: tire, suspension, A-arms, and fender) of a motor tricycle vehicle with two wheels in front. The main goal of the present work is to study the effect of the fender on the wheel subsystem drag a...

Foreseeing a permanent settlement on the moon, the astronauts will need a rover to explore the lunar environment on a daily basis. The goal of this project is to develop a new wheel that is able to provide more control, comfort, and drawbar pull in order to safely reach remote areas. Following a thorough design method, a new concept of flexible whe...

The growing interest in reducing fuel consumption and gas emissions provides an incentive for the automotive industry to innovate in the field of hybrid and plug-in hybrid electric vehicles. The two embedded power sources in these vehicles require an intelligent controller in order to make the best decision on the power distribution. Actually these...

Predicting the ageing behaviour of a lithium-ion battery is a challenging difficulty in plug-in hybrid electric vehicles applications. Invoking the expensive price of the energy density linked with considerable performances degradation over cycling, it is worth considering a battery lifetime optimization in the design process. The degradation will...

Aerospace panels are commonly restrained on complex inspection fixture jigs during the measurement process. Forces used to restrain the part are also monitored because of the part functional requirements. Given the difficulties in measuring these types of parts, this paper reviews the available fixtureless inspection methods with a focus on the cha...

Reducing the costs of bringing a new product to market is an objective common to all industries. In aeronautics, one of the options being pursued to achieve this goal is to eliminate the use of traditional engineering drawings from the product development process– chiefly by integrating a portion of the information normally contained in these drawi...

The paper is about a collaborative project focused on the design and fabrication of a cauldron for the Canada Games 2013, involving students from engineering and fine arts, along with trainees in welding and machining. However, the subject of this inquiry is more about the process that led to the completion of the cauldron than it is about the caul...

The recent increases in gasoline price have initiated a new thrust to reduce vehicle weight, hence creating a new market opportunity in the recreational product industry. At the same time, integration of both optimization and validation at the detailed design phase into the product development process has become key to achieving a product that meet...

At the present time, electric vehicles offer a considerably shorter autonomy than their internal combustion engine counterpart. To limit the chances of an energy shortage that drivers may experience, a method for accurate online forecasting of an electric vehicle residual range is proposed, thus strengthen-ing the interface and confidence between h...

The drag of an isolated rotating wheel subsystem including its accessories (tyre, suspension, A-arms and fender) of a tricycle vehicle has been studied both numerically and experimentally. The objective of this study is to validate the numerical model developed in order to optimise a generic wheel subsystem through drag analysis. The CAD model of t...

Hybrid and plug-in hybrid electric vehicles (HEV and PHEV) represent one of the best alternatives to conventional engine propelled vehicles since they are able to increase autonomy and reduce fuel consumption. Such vehicles require a high level control in order to establish the power split decision that minimizes fuel consumption while maintaining...

In a free state, nonrigid parts can take on different shapes compared to their design model. Such behavior of nonrigid parts introduces particular challenges to engineers during the geometric and dimensional requirements specification and inspection steps. Given that the choice of inspection method is guided by the requirement specification type, t...

A comprehensive modeling of the physics and dynamics of a realistic planing boat has been simulated. This study considers a two degree-of-freedom (DOF) unsteady model to investigate the equilibrium of the boat at steady speed and mimic the system dynamics properly. The numerical model consists of a planing hull with a waterjet pump inlet duct and a...

Engineering design is an iterative decision- making process involving interactions between three elements: geometry, materials and loads. The objective is to provide an optimum combination of these design parameters. Unfortunately, the absolute optimum can rarely be achieved because the design criteria typically place counter opposing demands and u...

Plug-in hybrid electric vehicles (PHEV) may carry a high amount of embedded electrical energy and provide the possibility to recharge it while not running. As a consequence, they will exhibit a relatively long range in full electric mode. Many kind of electric or hybrid vehicles are available or about to be developed. This paper presents a new conc...

Nonrigid parts are traditionally mounted on over-constrained holding fixtures during inspection in order to support the part and maintain an acceptable level of measurements repeatability and reproducibility. The fixture's over-constrained configuration and restraining sequence are critical characteristics of the fixture and can become active compo...

The expansion of the markets corroborated with product customization and short time to launch the product have led to new levels of competition among product development companies. To be successful in the globalization of the markets and to enable the evaluation and validation of products, companies have to develop methodologies focused on lifecycl...

Effective engineering-change management (ECM) is a real challenge in mechanical engineering industry and manufacturing companies. Computer-aided design systems are usually connected to other systems such as ERP or product data management, but currently this integration does not provide effective means to manage engineering change (EC). While commun...

In a free state, flexible parts may have different shapes compared to their computer-aided design (CAD) model. Such parts may likewise undergo large deformations depending on their space orientation. These conditions severely restrict the feasibility of inspecting flexible parts without restricting the deformations of the part and therefore require...

This paper presents a geometrical model that uses points and line segments to describe mechanisms at the early phases of the product design process. This model allows the description of an object with a topological matrix and another matrix that contains the metric information about the object. The paper also indicates how to associate two objects...

This paper proposes to investigate the use of a coordinate free approach for the mapping of geometrical requirements along the product life cycle. The geometry of the studied assembly is represented using a Gram matrix that is derived from a parametric model constituted of points and vectors. This parametric model is updated for all the relevant ph...

This paper presents the results of ongoing research aimed at developing an integrated computer-aided tolerancing tool. A unified Jacobian-Torsor approach has been developed for deterministic (worst case) computer-aided tolerancing. The paper describes how one can use the same set of interval-based deterministic equations in a statistical context. T...

When a new product is designed in an industrial context, it must be possible to produce this product with the desired level of quality and at an acceptable cost for the market. One of the important quality criteria is compliance with functional tolerances. To evaluate the impact of manufacturing defects on the quality of parts produced, designers s...

This paper proposes to investigate the use of a coordinate free approach for the mapping of geometrical requirement along a product life cycle. The geometry of the studied assembly is represented using a Gram matrix that is issued from a parametric model constituted of points and vectors. This parametric model is instanced for all relevant phase of...

In product lifecycle management, the efficiency of information reuse relies on the definition and management of equivalence information between various product data and structure representations. Equivalence information ensures the consistency and traceability of product information throughout the product lifecycle. The sales-delivery process of en...

This paper presents a framework for the calculation of functional requirements at several stages of the product life cycle. It uses the TTRS/MGRE concept for the determination of dimension chains. The geometry of the assembly is represented using a parametric model constituted of points and vectors. Finally, it also integrates the calculation of pa...

The great majority of engineered products are subject to thermo-mechanical loads which vary with the product environment during the various phases of its life-cycle (machining, assembly, intended service use...). Those load variations may result in different values of the parts nominal dimensions, which in turn generate corresponding variation of t...

Computer-aided design organizations worry much about the management of the communication between the various multidisciplinary teams working on the same project. The good management of this communication is very important for the success of the engineering change management process. Each discipline must approve or reject a change request according...

To perform tolerance analysis in machining, a combined approach which blends the benefits of the Model of Manufactured Part (the MMP model) and the Jacobian-Torsor model is proposed. The former is based on the CAD nominal model, where deviations are described relative to the nominal part using small displacement torsor. The later starts with the ki...

Product Lifecycle Management (PLM) is an approach for controlling and exploiting product-related information throughout its lifecycle as needed by various business functions. Concurrent engineering (CE) integrates several disciplines contributing to product design. Both PLM and CE involve information sharing amongst disciplines having a specific po...

The availability of three-dimensional tools for simulation and management of geometric uncertainties in CAD systems bear a strategic importance for the reduction in the number of physical prototypes and for the decrease in time to market. However, in spite of a growing interest for the various approaches which were proposed in this domain and in sp...

This paper describes a novel method for implementing tolerance synthesis by decoupled inversion of the Jacobian-torsor tolerance analysis model. Earlier work showed that a coupled pseudo inversion of the nonsquare Jacobian matrix implements an equal repartition of the functional requirement interval over all part tolerances involved in the chain, w...

In this paper we present an analytical solution to symmetrical water impact problems of a two-dimensional wedge. Unlike previous studies, we have taken into account the effect of velocity reduction of the solid body upon impact in order to determine impact pressure as well as the overall force acting on the body. This feature of our study provides...

This paper describes how the unified Jacobian-Torsor model can be used for the redesign of assembly tolerances. Through a numerical and graphical approach, the designer is guided into choosing his tolerances. After having identified a functional requirement (FR) and the functional elements (FEs) of the dimensional chain, it becomes possible to comp...

Work in various stages of the design process is often done in various subsidiary companies of an organization. These tasks can belong to different fields of expertise: electrical, mechanical, hydraulic etc. but still are dependent on each other. The various tasks must in fact respect all requirements so that the electrical system for example, fits...

Product design integrates several disciplines in a concurrent engineering (CE) environment. Each one of these disciplines has a specific point of view on the product being developed. While each discipline exerts its own expertise and methods on the definition of the product and its related processes, information must remain consistent for all disci...

In this paper, we report the results of our experimental investigation of the pressure distribution on a free-falling wedge upon entering water. Parameters such as the drop height, the deadrise angle and the mass of the wedge are related to the water pressure on the wedge and its dynamic behavior. Existing models that assumed a constant water-entry...

Engineering change management of mechanical products is a critical task which poses many challenges for industrials. Both the integration of the various tools intervening in the life cycle of a product and the management of the communication between the various multidisciplinary teams working on a product are difficult tasks. The communication betw...

This paper presents a modeling approach that can be used as an engineering design tool to predict the effects of various design choices on product quality. The mathematical model provides a rigorous functional relationship between dependent and independent variables. The dependent variables quantify product quality in the physical domain in terms o...

Because of uncertainties in manufacturing processes, a mechanical part always shows variations in its geometrical characteristics (ex. form, dimension, orientation and position). Quality then often reflect how well tolerances and hence, functional requirements, are being achieved by the manufacturing processes in the final product. From a design pe...

This paper presents the adaptation of tolerance transfer techniques to a model called TTRS for Technologically and Topologically Related Surfaces. According to this model, any three-dimensional part can be represented as a succession of surface associations forming a tree. Additional tolerancing information can be associated to each surface associa...

This paper presents the adaptation of tolerance transfer techniques to a model called TTRS for Technologically and Topologically Related Surfaces. According to this model, any three-dimensional part can be represented as a succession of surface associations forming a tree. Additional tolerancing information can be associated to each surface associa...

This paper presents a unified model for computer-aided tolerancing. It combines the benefits of the Jacobian matrix model and the torsor (or screw) model. The former is based on small displacements modeling of points using 6x6 transformation matrices of open kinematic chains in robotics. The latter models the boundaries of 3-D tolerance zones resul...

In current engineering practices, tolerancing activities are most often being done at the detail design phase, once drawings have been generated. The effects of tolerances are then propagated to other views of the product, such as process planning or quality control, where they will dictate choices of means and methods. Such an approach goes agains...

This paper presents a multi-agent architecture and a supporting data structure suited for the verification of constraints in a mechanical engineering design context. The data structure is composed of three levels, namely an environment level, providing a link to existing mechanical engineering software, an expert level, capturing product requiremen...

This paper presents a model for computer-aided tolerancing which enables to perform tolerance analysis and tolerance synthesis in both deterministic or statistical situations. The model combines the benefits of the Jacobian and torsor approaches developed for computer aided tolerancing. The proposed unified model is formulated using interval-based...

This paper presents a multi-agent architecture and a supporting data structure suited for the verification of constraints in a mechanical engineering design context. The data structure is composed of three levels, namely an environment level, providing a link to existing mechanical engineering software, an expert level, capturing product requiremen...

This paper presents an efficient, noncontact measurement technique for the automatic identification of the real kinematic parameters of an industrial robot. The technique is based on least-squares analysis and on the Hayati and Mirmirani kinematic modeling convention for closed kinematic chains. The measurement system consists of a single camera mo...

This paper presents a comparison between two currently available tools used to mathematically model the contribution of toleranced dimensions on critical quality requirements of an assembly, namely the screw based approach and the Jacobian based approach. It is shown that both models are actually equivalent, in the sense that the Jacobian based mod...

Computer Aided Design systems still suffer from a number of shortcomings with regards to the full design process: they provide limited solutions for maintaining product data consistency and offer no assistance to relieve designers from tedious, repetitive, solid modeling work. This paper presents a framework for improved support of the design proce...

This paper presents a mathematical representation of the three dimensional tolerance zones defined in the ANSI Y14.5 M standard. The tolerance zone models are based on the small displacement screw which is a screw parameter expressing first order approximation of traditional homogeneous transformation matrix. Modeling of datum system and complex su...

This paper presents the adaptation of tolerance transfer techniques to a model called TTRS for Technologically and Topologically Related Surfaces. According to this model, design and process plan specifications can both be represented as a succession of surface associations on a combined representation tree. This tree can be enriched by the additio...

The methodology employs a TTRS (Technologically and Topologically Related Surfaces) structure and consists of three stages : The user starts by constructing the TTRS structure in relation to the geometry and tolerancing that he wants to apply to a given mechanism. Using screw parameters associated with TTRS it is then possible to generate equations...

This paper presents a matrix approach coupled to the notion of constraints for the representation of tolerance zones within CAD/CAM (computer-aided design and manufacture) systems. The proposed theory, reproduces themeasurable ornon-invariant displacements associated with various types of tolerance zone. This is done using the homogeneous transform...

This paper presents a systematic approach for dimensioning and tolerancing mechanisms. The method is based on a model of Technologically and Topologically Related Surfaces (TTRS) and uses a binding graph representation of the mechanism. The complete dimensioning and tolerancing of each part is generated by recursively associating surfaces along kin...

A model called TTRS for technologically and topologically related surfaces, has been developed and its application to dimensioning and tolerancing is presented here. According to this model, any part can be represented as a succession of binary surfaces associations forming a tree. Additionally, each surfaces association, termed as a TTRS object, i...