Revistas
Revista:
VEHICLE SYSTEM DYNAMICS
ISSN:
0042-3114
Año:
2020
Vol.:
58
N°:
2
Págs.:
229 - 248
A full explicit FEM simulation of wheelset passing through switch panel is presented. The real 3D geometry of the switch panel is used, both vertical and lateral response are taken into consideration. The dynamic interaction is analysed and it is found that the damage mechanism on the switch blade and stock rail is a complex interaction of wear, fatigue and impact, which can be well described by explicit FEM simulation. Parametric analysis of running speed, traction coefficient and the friction coefficient between switch blade gauge surface and wheel flange indicate that decreasing running speed can help to reduce the damage on switch panel. The traction coefficient has little influence on the maximum impact response, but a higher traction coefficient is beneficial for eliminating the dynamic response after the maximum impact response point. The influence of the friction coefficient on the dynamic impact response is not significant, but a lower friction coefficient is favourable for decreasing the wear damage on the switch blade and increasing running safety. This work can provide a good understanding of the interaction on switch panel and give theoretical support for maintenance and improving the design.
Revista:
RAPID PROTOTYPING JOURNAL
ISSN:
1355-2546
Año:
2016
Vol.:
22
N°:
2
Págs.:
311 - 321
Purpose - This paper aims to focus on the design, analysis and additive manufacturing (AM) with two different technologies of an accelerator pedal for the Formula Student 2014 edition to reduce the weight of the original pedal in aluminium and maintain a reasonable level of performance. Design/methodology/approach - The new and the original accelerator pedals were modelled in a computer-aided design application, and three finite element simulations were performed for each manufacturing technology to evaluate three different driving scenarios. Later on, two physical prototypes were manufactured using two AM technologies: poly-jet and fused deposition modelling (FDM). With these physical prototypes, static tests were carried out to verify the computational simulations and to determine the fracture load, while dynamic tests, based on an input signal from a real racing scenario, were performed to ensure their technical viability. Findings - Simulations with poly-jet and FDM printing material show that the new design presents a maximum deformation of 4.8 and 4.09 mm, respectively, under a nominal load of 150N. The results of the static tests with the poly-jet physical prototype showed a maximum displacement of 4.05 mm under a nominal load of 150N, while the ultimate load before fracture was 450N. The FDM prototype reached 3.98 mm under 150N and the ultimate load was 350N. Dynamic tests showed that both pedals were able to withstand four Formula Student "Endurance" events without failure. Originality/value - This paper states that AM approach is a feasible and economically affordable solution in comparison to exiting solutions with metallic alloys and composite materials when designing and manufacturing accelerator pedal arms for Formula Student competition cars. According to these results, the present research argues that, from a technical point of view, the AM pedals stand at a reasonable level of performance in displacements and stresses. This study suggests that AM pedals could be a viable option that must be considered in professional competitive automobiles.
Revista:
INTERNATIONAL JOURNAL OF ENGINEERING EDUCATION
ISSN:
0949-149X
Año:
2015
Vol.:
31
N°:
1
Págs.:
209 - 219
Formula Student (also known as Formula SAE) is an international competition for universities that challenges the students with a comprehensive engineering problem. Most of the participant universities and all the companies involved in the organization of the competition have identified this event as the most suitable tool for hard and soft skills development. This paper evaluates this development by means of two different objective assessments in the frame of a specific team, identifying the potential of the competition and showing a particular approach to enhance soft skills development.
Revista:
VIRTUAL AND PHYSICAL PROTOTYPING
ISSN:
1745-2759
Año:
2015
Vol.:
10
N°:
3
Págs.:
149 - 162
Formula Student is an international competition governed by the Society of Automotive Engineers (SAE) which challenges university students to design and build a racing car that will subsequently be compared against other cars from universities around the world on homologated racing circuits by non-professional drivers. This study focuses on the design, analysis and manufacturing process of a new oil sump for a Formula Student car - which involves combining a main ABS-plastic core created by an additive manufacturing (AM) printing process and a manual lay-up process with carbon fibre - in order to reduce the sloshing effect due to the movement of the oil during racing. The new oil sump and the original sump were modelled with computer-aided design (CAD) software and five computational fluid dynamics (CFD) simulations were performed to compare the sloshing effect in both designs in three driving scenarios: acceleration, braking and changing direction. The simulations showed that acceleration is not a critical situation since the new internal design of the sump was capable of delaying the immersion time of the oil pick-up pipe from 0.75 seconds to 2 seconds during braking and from 0.4 seconds to 0.8 seconds during lateral acceleration. The new design was physically manufactured and subsequently integrated into an internal combustion engine for testing for 45 minutes. During this test, the engine was started and put at 9600 RPM, so the oil worked under realistic temperature condi
Revista:
INGENIERIA E INVESTIGACION
ISSN:
0120-5609
Año:
2015
Vol.:
35
N°:
3
Págs.:
115 - 120
This paper presents a change made to the lecturing approach used within a specific course. The new lecturing approach is based on a non-linear structure where each lesson combines concepts from different topics, in contrast to the traditional linear structure in which each topic is treated separately. The objective of the non-linear approach is to increase student dynamism and motivation and to foster teacher-student dialog. Assessments from students who were taught according to the traditional linear structure along with assessments from students who were taught under both the linear and non-linear approaches are presented. Results show that the non-linear lecturing approach was welcomed and led to a higher degree of student dynamism and motivation and to more tea-cher-student dialog.
Revista:
INTERNATIONAL JOURNAL OF VEHICLE DESIGN
ISSN:
0143-3369
Año:
2014
Vol.:
64
N°:
42462
Págs.:
214 - 239
The Gas Damper (GD) uses gas as internal fluid, obtaining an important dependency on operating frequency and stroke amplitude. The potential performance of GD was analysed previously using a quarter-car model, and offered a new approach to the traditional ride/handling trade-off, especially in off-road vehicles. This paper studies the GD influence on a vehicle's performance using a more complete model (full-car) to confirm its suitability for that kind of vehicle and also to completely understand the GD behaviour. This is evaluated by assessing ride isolation, road-holding, body control and rollover stability, and is compared to the performance of a hydraulic suspension.
Revista:
VEHICLE SYSTEM DYNAMICS
ISSN:
0042-3114
Año:
2011
Vol.:
49
N°:
42401
Págs.:
199 - 218
The main characteristic of a gas damper (GD) is the use of gas as internal fluid, which offers an alternative to hydraulic shock absorbers. In this paper, a mathematical GD model is presented and validated. The use of a compressible fluid provides GD with a behaviour dependent on velocity, like conventional dampers, but also with a strong dependency on frequency and on stroke amplitude. This dependency allows an improvement in the traditional compromise between comfort and safety. A quarter-car model is used to evaluate the ride performance that can be expected using the GD, focusing on the cited compromise. Results are compared with the ride performance of a hydraulic shock absorber. Finally, a sensitivity study centred on the stiffness of the internal fluid is presented.