bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Design Resource Management Using Bayesian Network Embedded in Task Network Method
Authors: Xin Chen Hilario Lorenzo , Moullec Marie-Lise , Ball Nigel , Clarkson P. John 
Published: December 2016

In Product Development (PD), there is an inherent complexity in deciding what resources should perform which tasks taking into account their effectiveness towards completing the task, while adjusting to their availabilities. The right resources must be applied to the right tasks in the correct order. In this context, process modeling and simulation could aid in resource management decision making. However, most approaches define resources as elements needed to perform the activities without defining their characteristics, or use a single classification such as “designers”. Despite their crucial importance to the delivery of the product, resources such as computational hardware, software, testing resources, amongst others have been overlooked during process planning stages.
This paper presents a new method to model different resource types (designers, computational, testing) and studies the impact of using different options of those resources by simulating the model and analyzing the results. Thus, the new approach, which extends a task network model with Bayesian Networks (BN), allows testing the influence of using different resources on process performance. The method uses BN within each task to model different instances of resources that carries out the design activities (computational, designers and testing) along with its configurable attributes (time, risk, learning curve etc.), and tasks requirements. Thus, activity behavior is shaped depending on the chosen resource option to perform it. The approach enhances the capability to explore resource combination design space. It was applied to an aerospace case study to identify insights such as the best performing resource combinations, critical resources, resource sensitive activities, and the probability of a resource reaching performance targets.
Operation Modes Comparison of a Reconfigurable 3-PRS Parallel Manipulator Based on Kinematic Performance
Authors: Maraje Siddharth , Nurahmi Latifah , Caro Stéphane 
Published: December 2016

The 3-PRS parallel manipulator with different arrangements of prismatic joints is called a reconfigurable 3-PRS parallel manipulator in this paper. The three prismatic joints in PRS limbs are attached to the base with an angle α between the horizontal plane of the base and their directions. Based on [1], the manipulator has identical operation modes, namely x0 = 0 and x3 = 0 for any value of α. Accordingly, this paper presents in more details the performance evaluation of these operation modes by using the output transmission index (OTI) and the constraint transmission index (CTI). The OTI and CTI determine the force transmission efficiency and the constraining ability of the manipulators, respectively.
Initially, the determination of the number and types of operation modes of the 3-PRS parallel manipulator is recalled. The computation is carried out by using an algebraic approach, namely the Study kinematic mapping. In each operation mode, the actuation wrenches and the constraint wrenches are obtained based on the Screw theory. Then, the OTI and CTI are traced in the orientation workspace of the manipulator for different values of angle α. Furthermore, the singularity conditions are analysed corresponding to the values of OTI and CTI.
Effect of the Deformation of the Supporting Structure on the Measurement of the Inertia Properties of Vehicles
Authors: Previati Giorgio , Gobbi Massimiliano , Ballo Federico 
Published: December 2016

In the measurement of the inertia properties of rigid bodies (mass, centre of gravity location and inertia tensor) the structures carrying the body under test are usually considered to be rigid. This assumption is less and less satisfied as the dimensions of the body grow. Consequently, the forces exchanged between the body and the structures can be large enough to deform the structure and affect the measurement, especially the location of the centre of gravity.
In this paper, with special reference to the InTenso+ Measuring System of the Politecnico di Milano, the effects of the deformation of the test rig structure when measuring large bodies is investigated. A theoretical analysis is performed by using a flexible multibody mathematical model of the test rig. The deformation of the test rig is deeply investigated by a dedicated FEM model. The results of the theoretical analysis are then validated by measuring the inertia properties of a light truck.
It turns out that the deformation of the test rig can actually affect the measurement. This deformation can be compensated by a proper mathematical procedure. The method can, consequently, be employed also for very large bodies for which the construction of a sufficiently rigid structure as to neglect its deformation is practically impossible.
Vehicle Ride Evaluation on a Four-Post Rig: Is the Vertical Seat Component Sufficient?
Authors: Kat Cor-Jacques , Mendez Esteban , Els Pieter Schalk , Dhaens Miguel 
Published: December 2016

Ride has always been an important aspect in vehicle design, driven by the customer’s increasing demand for vehicles with better comfort. The vibrational response of the vehicle is one of many factors contributing to the overall ride perception, with road inputs being the major excitation source. The improved capabilities of vehicle simulation models and virtual proving grounds have supplemented experimental prototype testing for tuning suspensions. Final tuning, and ride evaluation, is however still done through physical on-road testing. Four-post rig tests hold potential cost and time savings when used appropriately in the development process.
The four-post rig imposes only vertical inputs at the tire contact patches and thus it is expected for the vertical response of the vehicle to be the dominant component. The objective of this paper is to determine whether ride comfort can sufficiently be evaluated on the four-post rig using only the vertical seat Component Ride Value (CRV). The response of an instrumented vehicle on the four-post rig was measured by a tri-axial seat pad accelerometer. Vertical, longitudinal and lateral seat CRVs as well as the seat Point Ride Value (PRV) were calculated from the measured seat acceleration in the three translational directions using the BS6841 (1987) standard. The PRV is the square root of the sums of squares of the three CRVs. The CRVs and PRV, obtained from tests at various speeds and road roughnesses, were analyzed to determine whether the vertical seat CRV is sufficient in capturing the perceived ride comfort.
Results showed that the longitudinal and lateral CRVs are in excess of 26% and 63%, respectively of the dominant vertical seat CRV over the various tests. This implies that the vertical seat CRV underestimated the discomfort when compared to the seat PRV. It was also observed that the three CRVs had different sensitivities to test parameters and conditions. For example, at different speeds over the same road roughness the longitudinal CRV increased significantly more than the other two components. The differences in sensitivities may be due to the specific boundary conditions imposed on the vehicle by the four-post rig. It is concluded that the vertical seat CRV may not be sufficient to evaluate the ride comfort on a four-post rig.
Virtual Acoustic Model for the Simulation of Passing Vehicle Noise
Authors: Siegel Antje , Weber Christian , Mahboob Atif , Albers Albert , Landes David , Behrendt Matthias 
Published: December 2016

In this paper a virtual acoustic model for the simulation of noise by passing vehicles is described. The underlying motivation for the acoustic model is the increasing demand for realistic traffic and acoustic disturbance simulation methods. For this purpose, simulation tools are desired, that allow simulation of different kinds of traffic scenarios within a Virtual Reality (VR) environment. This includes a plausible and realistic presentation of the acoustic situation. The virtual vehicle model introduced in this paper is composed of several individual sound sources, e.g. for the tires, the engine and the exhaust system. Each sound source has its own directional characteristics. These characteristics are considered by sets of digital filters for each sound source. For that purpose, measurement series with a car on a dynamometer were performed.
Furthermore, in order to consider the environmental conditions a method for the description of sound reflections at simple objects (e.g. plane walls) is explained in this paper. The implemented concept offers the possibility to create individual mirror sources for every initial sound source and every object that can cause reflections. Since the concept is intended for the interactive application, the described method works in real time.
In order to evaluate the described virtual acoustic model, a test with volunteers was performed. These examinations are also described and discussed in this paper.
Deriving Infill Design of Fused Deposition Modelled Parts From Predicted Stress Profiles
Authors: Gopsill James A. , Hicks Ben J. 
Published: December 2016

The use of Fused Deposition Modelling (FDM) is increasing rapidly in both the commercial and industrial sectors as a means of rapidly prototyping geometrically complex parts. Particular affordances of FDM include the reduction of waste material during manufacture, the use of multiple materials within a single manufacturing process and the ability to manipulate the internal geometry of a part. The latter of which has seen the generation of many 2-dimensional repeating pattern structures such as square, rectilinear and hexagonal, as well as an emerging field of 3-dimensional structures. Although these patterns have provided stiffness and rigidity whilst reducing the production time of FDM prototypes, many do not consider the actual loading conditions of the part in-situ, where it is argued that further significant gains in the performance could be achieved. This includes further reduction in process time and increased part functionality.
Thus, this paper presents initial work into the generation of an infill that is derived from the predicted stress profile for the part. This has been achieved through the post-processing of Finite Element (FE) models to identify the stress profile. Interpolation across these profiles leads to a set of aligned Bézier splines that enable the transmission of force and are also able to be manufactured using FDM. These splines are embedded within the typical slicing procedure of a part ahead of being manufactured on a FDM machine. Initial results from parts designed to support three-point bending loads show a 79% increase in the stiffness of the part alongside a consistent and repeatable mode of failure when compared to the commonly used honeycomb infill design.
Development of a Manufacturing Ontology for Functionally Graded Materials
Authors: Furini Francesco , Rai Rahul , Smith Barry , Colombo Giorgio , Krovi Venkat 
Published: December 2016

The development of manufacturing technologies for new materials involves the generation of large and continually evolving volumes of data. The analysis, integration and management of these data, typically stored in multiple independently developed databases, creates significant challenges for practitioners. Strategies which allow open sharing of pre-competitive data pertaining to engineering design can play a powerful role in enabling innovation, but these strategies can work only if the data themselves can be presented in a way that is both consistent and understandable to both humans and computers.
We believe that ontology applied to engineering (OE) represents a viable strategy for the alignment, reconciliation and integration of diverse and disparate data. The scope of OE includes: consistent capture of knowledge pertaining to the types of entities involved; facilitation of cooperation among diverse groups of experts; effective and flexible ongoing curation and update of data; and collaborative design and knowledge reuse.
We propose as case study an ontology for the domain of composite materials focusing in particular on the class of ‘Functionally Graded Materials’ (FGM) with examples drawn from the field of biomedical applications. The goal of the ontology is to provide information about the components of such materials, the manufacturing processes involved in their creation, and their applications, ranging from additive manufacturing to restorative dentistry. The ontology is developed using Basic Formal Ontology (BFO) and parts of the Ontology for Biomedical Investigation (OBI) and follows the best practice principles for ontology development codified in the OBO (Open Biomedical Ontologies) Foundry.
Effect of Surface Roughness in Micro Injection Moulding Process of Thin Cavities
Authors: Bellantone Vincenzo , Surace Rossella , Modica Francesco , Fassi Irene 
Published: December 2016

Due to its ability to produce low-cost and high repeatable micro polymeric parts, injection moulding of micro components is emerging as one of the most promising enabling technologies for the manufacturing of polymeric micro-parts in in many different fields, from IT to Healthcare, to Medicine.
However, when approaching the micro-scale, different issues related to the process should be addressed, especially as the depth of the mould cavity becomes very thin. In particular, the mould roughness could affect the surface quality of the produced micro components, like in macro moulding, as well as the complete filling of the parts. Although micro-injection moulding process has been extensively studied, further research on the effect of mould roughness conditions and on non-Newtonian fluid flow in micro-cavities are required. This will shed a light and open up new paths for a deeper understanding of the moulding scenario.
The main objective of the present paper is the evaluation of the influence of the mould roughness on the polymer flow during micro injection moulding process. The test parts have been realized in POM material and have thickness lower than 250 μm. The test part design has been properly conceived in order to neglect the effect of dimensions and geometry and to highlight the roughness contribution during the filling phase of micro injection moulding process. The experimentation has been performed considering cavities with different roughness values (3 levels) and decreasing depths (3 levels), for a total of nine test parts manufactured by micro-electrical discharge machining process (μ-EDM).
The results of the experiments are discussed in the paper and show that cavity surface roughness affects the injection process as the moulding scale level is decreased. In particular, when the cavity depths are reduced, higher surface roughness promotes the filling of components and this finding could be ascribed to the increase of wall slip effect.
Thermo-Elastic Modelling of High Performance Braking Systems
Authors: Gobbi Massimiliano , Mastinu Giampiero , Previati Giorgio , Cantoni Carlo , Passoni Raffaello 
Published: December 2016

The thermal and structural behaviour of carbon-carbon disc brake and pads have been studied.
A literature review was conducted to investigate recent research that has been completed in many areas related to thermo-elastic modelling of braking systems.
The friction forces generated during braking between brake pads and disc produce high thermal gradients on the rubbing surfaces. Thermo-elastic deformation results in contact concentration, leading to the non uniform distribution of temperature and pressure making the disc susceptible to hot bands and hot spots formation.
The present paper proposes a simplified modelling concept useful in the preliminary brake system design phase. Furthermore, a full finite element model related to structural/thermal analysis is presented as well. The thermo-elastic behaviour has been investigated experimentally under different braking conditions.
The models (simplified and full FE) have been validated experimentally on the basis of indoor tests results.
The accuracy of the two models is good, but the computational effort required by the full FE model can be very high.
Characterizing Competencies for Human-Centered Design
Authors: Kramer Julia , Agogino Alice M. , Roschuni Celeste 
Published: December 2016

Employees and employers alike increasingly value human-centered design, as it can drive innovation across a wide range of industries. With the growing interest in understanding human-centered design processes as they apply in different professions, there is a rising need to recognize the specific competencies necessary to perform these jobs well. Though there is a body of research on how people discover, create, and use design methods, there is a lack of understanding of what core competencies are necessary for people to apply these methods. Previous interactions with target users of theDesignExchange, an interactive community-driven portal to support design researchers and practitioners, have demonstrated a desire for increased awareness of the competencies required for employability and for successful design practice. This paper reports on a portion of an expansive competency-finding project aimed at identifying the core set of competencies that human-centered design practitioners need and employers seek.
In this paper, we present our lists of cultivated mindsets, specialized disciplinary skills, contextualized tasks, and basic skills in human-centered design. These lists represent a first pass at identifying the essential and underlying competencies a practicing or aspiring human-centered designer must have in order to perform their current or future design tasks. The work we present in this paper serves as a preliminary starting point for future research interviews with design practitioners and employers, as we seek to understand human-centered design competencies.
Automated 1st Order Tolerancing: Schema Generation
Authors: Hejazi Sayed Mohammad , Biswas Deepanjan , Venkiteswaran Adarsh , Shah Jami J. , Davidson Joseph K. 
Published: December 2016

Tolerances are specified by a designer to allow reasonable freedom to a manufacturer for imperfections and inherent variability without compromising performance. A group of tolerance classes, tolerance values and datums specified in design that control the variations in a part to be manufactured, is called a tolerance scheme. It takes knowledge and experience to create a good tolerance scheme. It is a tedious process driven by the type of parts, their features and controls needed for each one of them. In this paper, we investigate the development and implementation of 1st order automated Geometric Dimensioning and Tolerancing (GD&T) schema generation. Prior to schema generation, some assembly information such as presence of assembly features and pattern features in the given assembly CAD file is required. Mohan et al [6] proposed and implemented 3 preprocessing modules which provides required assembly information. Rao [8] developed and reported 5 experiential GD&T rulesets that could help the process of auto-tolerancing. Haghighi et al [5] proposed a procedure for automating 1st order GD&T schema generation and value allocation based on the provided assembly information and using GD&T rulesets. In this paper we present the development and implementation of 1st order GD&T schema generation. The output of this toolset is a complete GD&T schema for given assembly without tolerance values. Biswas et al [12] proposed and developed a toolset for tolerance value allocation and analysis. Once GD&T schema is generated and tolerance values are allocated, recommended GD&T is translated into STEP AP242 file format. Venkiteswaran et al [13] developed a module that reads the nominal geometry in STEP AP203 and GD&T information in CTF format and translates it to STEP AP242.
Combining all these 3 modules with pre-processing modules leads to the completion of 1st order auto-tolerancing.
The Development and Effects of Teaching Perspective Free-Hand Sketching in Engineering Design
Authors: Hilton Ethan , Li Wayne , Newton Sunni H. , Alemdar Meltem , Pucha Raghuram , Linsey Julie 
Published: December 2016

As Computer-Aided Design software has become more advanced, the use of hand-drawn engineering drawings has greatly diminished. This reduction has led to free-hand sketching becoming less emphasized in engineering education. While many engineering curriculums formerly included courses dedicated entirely to sketching and hand drafting, these topics are no longer addressed by most current curriculums. However, it has been observed that sketching has many benefits including improved communication in the design process, idea generation exercises, and visualizing design ideas in three-dimensional space. While isometric sketching has long been the preferred method in engineering curriculums, there are benefits of teaching perspective sketching including the creation of more realistic sketches for communication and idea generation.
This paper presents the development of a perspective-based sketching curriculum and the study of how this method compares to more traditional methods of teaching sketching to students in a freshman level engineering graphics course.
The results show that the perspective-based sketching method leads to equivalent gains in spatial visualization skills and final design self-efficacy as the traditional method of teaching hand sketching. While maintaining these skills, the new method also taught students additional skills. Through surveys and interviews, the students expressed that these skills would be useful to them in their future coursework and careers.
Investigation of the Effectiveness of Multi-Fidelity Surrogates on Extrapolation
Authors: Park Chanyoung , Haftka Raphael T. , Kim Nam H. 
Published: December 2016

Surrogates have been used as an approximate tool to emulate simulation responses based on a handful of response samples. However, for high fidelity simulations, often only a small number samples are affordable, and this increases the risk of extrapolation using surrogates. Frequently, most of the sampling domain is not in the interpolation domain (called coverage), usually defined as the convex hull of these samples. For example, when we build a surrogate with 20 samples in six-dimensional space, the coverage is merely 2% of the sampling domain. Multi-fidelity surrogates (MFS) may mitigate this problem, because they use large number of low fidelity simulations, so that most of the domain is covered with at least some simulations.
This paper explores the extrapolation capability of MFS frameworks through examples including algebraic functions. To examine the effects of different MFS frameworks, we consider six MFS frameworks in terms of their functional forms and frameworks for fitting the forms to data. We consider three different functional forms based on different approaches: 1) a model discrepancy function, 2) model calibration, and 3) both. Bayesian MFS frameworks based on the functional forms are considered. We include also their counterparts in simple frameworks, which have the same functional form but can be built with ready-made surrogates. We examined the effect of the high fidelity sample coverage on extrapolation while the number of high fidelity samples remains the same. The root mean square errors (RMSE) of the interpolation and extrapolation domains are calculated to see their effectiveness on the overall RMSE of whole MFS. For the examples considered, we found that the presence of a regression scalar could be important to extrapolation. Bayesian framework is useful to find a good regression scalar, which simplifies the discrepancy function.