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SP-B1 Reviewers’ General Comments. Reviewers’ General Comments: It may be said that a relevant amount of the planned activity has been completed and the outcomes are basically corresponding to the targets. There are two points which still need a relevant effort by the involved partners:
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SP-B1 Reviewers’ General Comments • Reviewers’ General Comments: • It may be said that a relevant amount of the planned activity has been completed and the outcomes are basically corresponding to the targets. • There are two points which still need a relevant effort by the involved partners: • 1. The safety issue of the integrated rear module needs to be assessed, in order to define the final design in due time for the construction/testing phase of the demonstrator vehicle. • 2. The CNG storage vessels need an implementation in order to fulfil the burst test in the area of bosses when dropped vertically on each dome, in order to avoid possible indentation in the case of rear side impact to the vehicle. • Of course, both problems are highly interrelated and the partners should work with tight collaboration.
SP-B1 Reviewers’ Specific Comments – Deliverable DB1.11 • DB1.11: Virtual design of advanced vehicle platform, with functionalized rear module • It may be said that the task was mostly fulfilled, but some clarifications are needed about the vehicles: • The C-Segment Bravo was defined as “Demonstrator Vehicle” (see e.g. PR1 –pg. 21) but also “Validator Vehicle”. • The B-segment Grande Punto has to be considered a demonstrator vehicle, to be developed by “virtual design”. • The question is: Why was the validator vehicle Bravo provided with 2 additional tanks under the rear seats (C and D of fig. 4 – DA 1.13), while the solution of a single longitudinal additional tank was already defined? (The solution of the rear module with 3 tanks + a single longitudinal one was already defined during the first quarter of 2010). • It is repeatedly stated that the tanks in the rear module can give some contribution to the structural stiffness of the vehicle, but this is not allowed by the current regulations on the matter, and this has already been outlined during the first Review Meeting. • Concerning the safety issues, it is said that maybe some redesign of the overall layout will have to be considered (options to improve safety performance with respect to a rear –impact crash, pg. 19 - fig. 16), but time and additional costs, in such an event, are not mentioned.
SP-B1 Reviewers’ Specific Comments – Deliverable DB1.11 • DB1.11: Virtual design of advanced vehicle platform, with functionalized rear module • It may be said that the task was mostly fulfilled, but some clarifications are needed about the vehicles: • The C-Segment Bravo was defined as “Demonstrator Vehicle” (see e.g. PR1 –pg. 21) but also “Validator Vehicle”. • The B-segment Grande Punto has to be considered a demonstrator vehicle, to be developed by “virtual design”. • The question is: Why was the validator vehicle Bravo provided with 2 additional tanks under the rear seats (C and D of fig. 4 – DA 1.13), while the solution of a single longitudinal additional tank was already defined? (The solution of the rear module with 3 tanks + a single longitudinal one was already defined during the first quarter of 2010). • It is repeatedly stated that the tanks in the rear module can give some contribution to the structural stiffness of the vehicle, but this is not allowed by the current regulations on the matter, and this has already been outlined during the first Review Meeting. • Concerning the safety issues, it is said that maybe some redesign of the overall layout will have to be considered (options to improve safety performance with respect to a rear –impact crash, pg. 19 - fig. 16), but time and additional costs, in such an event, are not mentioned.
SP-B1 Response to Comment 1 and Deliverable DB1.11 • The C-segment Fiat Bravo can be defined as both “Demonstrator Vehicle” but also “Validator Vehicle”: • The Fiat Bravo can be considered to demonstrate in part the technical solutions being developed in SP-B1, particularly as regards the lightweight, low-cost composite vessels (WP B1.2) and the advanced electronic pressure regulator and in-tank valves (WP B1.3), while also validating the solutions being developed in SP-A1. • The Fiat Bravo corresponds to (physical) Deliverable DA1.13 (whereas it is not a Deliverable of SP-B1). • The B-segment Fiat Grande Punto is the demonstrator vehicle for SP-B1, being the subject of the development by “virtual design” in WP B1.5. • The intention is to also physically realize the Fiat Grande Punto with Advanced CNG Storage Module, as indicated in the original DoW (although the physical demonstrator vehicle is not included in the list of Deliverables for SP-B1).
SP-B1 Reviewers’ Specific Comments – Deliverable DB1.11 • DB1.11: Virtual design of advanced vehicle platform, with functionalized rear module • It may be said that the task was mostly fulfilled, but some clarifications are needed about the vehicles: • The C-Segment Bravo was defined as “Demonstrator Vehicle” (see e.g. PR1 –pg. 21) but also “Validator Vehicle”. • The B-segment Grande Punto has to be considered a demonstrator vehicle, to be developed by “virtual design”. • The question is: Why was the validator vehicle Bravo provided with 2 additional tanks under the rear seats (C and D of fig. 4 – DA 1.13), while the solution of a single longitudinal additional tank was already defined? (The solution of the rear module with 3 tanks + a single longitudinal one was already defined during the first quarter of 2010). • It is repeatedly stated that the tanks in the rear module can give some contribution to the structural stiffness of the vehicle, but this is not allowed by the current regulations on the matter, and this has already been outlined during the first Review Meeting. • Concerning the safety issues, it is said that maybe some redesign of the overall layout will have to be considered (options to improve safety performance with respect to a rear –impact crash, pg. 19 - fig. 16), but time and additional costs, in such an event, are not mentioned.
SP-B1 Response to Comment 1 and Deliverable DB1.11 • As regards the confusion concerning the layout of the tanks on the two vehicles: • The C-Segment Fiat Bravo does not allow the installation of a cylinder in the tunnel (ie. longitudinal orientation) since the section is too narrow and shallow. • The layout of vessels on the Fiat Bravo:
SP-B1 Response to Comment 1 and Deliverable DB1.11 The layout of vessels on the Fiat Bravo:
SP-B1 Response to Comment 1 and Deliverable DB1.11 The layout of vessels on the Fiat Bravo:
SP-B1 Response to Comment 1 and Deliverable DB1.11 The layout of vessels on the Fiat Bravo:
SP-B1 Response to Comment 1 and Deliverable DB1.11 Instead the B-Segment Grande Punto vehicle does allow room for the installation of a cylinder in the tunnel (ie. longitudinal orientation). Indeed, on the current production CNG “Natural Power” version of the vehicle a Type 1 vessel is strap-mounted in the tunnel. From the virtual design study of WP B1.5 which is currently on-going, the proposal is to substitute the current-production, strap-mounted Type 1 vessels with a neck-mounted Type IV vessel.
SP-B1 Response to Comment 1 and Deliverable DB1.11 This configuration will be analysed in detail during the Virtual Integration and Performance assessment activities of Tasks B1.5.1 and B1.5.2 respectively.
SP-B1 Reviewers’ Specific Comments – Deliverable DB1.11 • DB1.11: Virtual design of advanced vehicle platform, with functionalized rear module • It may be said that the task was mostly fulfilled, but some clarifications are needed about the vehicles: • The C-Segment Bravo was defined as “Demonstrator Vehicle” (see e.g. PR1 –pg. 21) but also “Validator Vehicle”. • The B-segment Grande Punto has to be considered a demonstrator vehicle, to be developed by “virtual design”. • The question is: Why was the validator vehicle Bravo provided with 2 additional tanks under the rear seats (C and D of fig. 4 – DA 1.13), while the solution of a single longitudinal additional tank was already defined? (The solution of the rear module with 3 tanks + a single longitudinal one was already defined during the first quarter of 2010). • It is repeatedly stated that the tanks in the rear module can give some contribution to the structural stiffness of the vehicle, but this is not allowed by the current regulations on the matter, and this has already been outlined during the first Review Meeting. • Concerning the safety issues, it is said that maybe some redesign of the overall layout will have to be considered (options to improve safety performance with respect to a rear –impact crash, pg. 19 - fig. 16), but time and additional costs, in such an event, are not mentioned.
SP-B1 Response to Comment 1 and Deliverable DB1.11 Before the first Review Meeting the possibility that the tanks also provide some contribution to the structural stiffness of the vehicle had been contemplated since the DoW (on p.35) states the following: “WP B1.4 Storage Module Concepts – Virtual design of highly integrated storage module is developed, investigating different vehicle packaging based on concepts. In order to overcome the limitations of current solutions, that require an off-line assembly of the module, this phase of the project will focus on exploring the feasibility of an innovative concept in which the entire rear section of the vehicle platform is re-designed in order to act as a storage module itself. A possible realization of this idea could consist in substituting the rear portion of a conventional body structure, which is based on stamped metal sheets, with a space-frame concept comprising nodes and profiled beams: this space-frame concept would allow the easier integration of different cylinder types (Type 1 to Type 4) and could be further improved from a vehicle design for improved safety and weight by using the vessels themselves as part of the structure…..”
SP-B1 Response to Comment 1 and Deliverable DB1.11 However, following the first Review Meeting, this idea was abandoned as soon as it became clear that the current regulations on the matter had to be respected rather than pursuing an alternative, more innovative approach. Correspondingly, in DB 1.11 “Virtual design of advanced vehicle platform, with functionalized rear module” it is stated that: “The typical torsional stiffness of a B-segment car body is of the order of 60000 daNm/rad; correspondingly the addition of the functionalise rear CNG storage module should enable an increase of stiffness of approx. 3%. As indicated previously, the contribution of the module to the global car body stiffness is limited by the flexibility of the rubber bushings at the attachment points which are designed to have a stiffness of shore 70 (axial stiffness of approx. 700 daN/mm and torsional stiffness of approx. 800 daNm/rad) so as to not unduly constrain the vessels in their axial direction.”
SP-B1 Response to Comment 1 and Deliverable DB1.11 Furthermore, in the Milestone Report M.B1.3 “Concept for advanced storage module” released in October 2010, it is stated in Section 2.3 “Mounting of the vessels in the functionalized rear module” (p.13) that : “In the design of the functionalised rear module, of specific relevance is the solution which has been developed for the fixing of the vessels to the frame. Fig. 10 shows the neck mounting solution which has been proposed in which brackets are used to anchor the vessels to the frame. At the valve-end of the vessel, a rubber ring of thickness 3 mm is interposed between the neck of the vessel and the brackets in order to facilitate alignment during assembly; instead, at the opposite end, a bushing is included to permit the axial deformation of the cylinders under the effect of the working pressure (200 bar). Furthermore, during a crash event, this mounting solution will also serve to reduce the loading on the vessels, as will be investigated during the activities of WP1.5.2. It should be noted that, with respect to the mounting solution described in Deliverable D.B1.11, this limits the contribution of the storage module to the increase in stiffness of the rear section of the vehicle but improves the crashworthiness of the vehicle in the case of side and rear impact. (The complete analysis of design solutions in terms of safety and stiffness, will be documented in Deliverable DB1.16 due Month 36).”
SP-B1 Response to Comment 1 and Deliverable DB1.11 • Currently, in order avoid contribution to the structural stiffness of the vehicle in accordance with R110, the proposal is use bushings in the neck-mounting configuration with the following stiffness values: • Axial 36 daN/mm • Radial 160 daN/mm
SP-B1 Reviewers’ Specific Comments – Deliverable DB1.11 • DB1.11: Virtual design of advanced vehicle platform, with functionalized rear module • It may be said that the task was mostly fulfilled, but some clarifications are needed about the vehicles: • The C-Segment Bravo was defined as “Demonstrator Vehicle” (see e.g. PR1 –pg. 21) but also “Validator Vehicle”. • The B-segment Grande Punto has to be considered a demonstrator vehicle, to be developed by “virtual design”. • The question is: Why was the validator vehicle Bravo provided with 2 additional tanks under the rear seats (C and D of fig. 4 – DA 1.13), while the solution of a single longitudinal additional tank was already defined? (The solution of the rear module with 3 tanks + a single longitudinal one was already defined during the first quarter of 2010). • It is repeatedly stated that the tanks in the rear module can give some contribution to the structural stiffness of the vehicle, but this is not allowed by the current regulations on the matter, and this has already been outlined during the first Review Meeting. • Concerning the safety issues, it is said that maybe some redesign of the overall layout will have to be considered (options to improve safety performance with respect to a rear –impact crash, pg. 19 - fig. 16), but time and additional costs, in such an event, are not mentioned.
SP-B1 Response to Comment 1 and Deliverable DB1.11 • Concerning the safety issues for the B-Segment Grande Punto , as already stated in the response to the Review of the first 12 months: • “The solution for securing the vessels to the frame which has been proposed by CRF is indeed innovative, the intention being to improve the structural properties of the rear section of the vehicle by exploiting the stiffness of the vessels themselves. As indicated by the reviewer(s), this may indeed prove to be critical with respect to the crash analyses. • However it should be pointed out also that a relatively significant deformation space around the storage module sub-assembly does exist when mounted within the chassis of the vehicle. • Fall-back options (ie. in the case of inadequate crash behaviour during simulation) would be to: • re-design the rear overhang of the vehicle in order to increase the deformation space further; • adopt deformable brackets, in longitudinal direction, under rear crash loads; • use a more conventional belt-type solution requiring a re-design of the frame and brackets. • In any case such a re-design could be included as part of the ‘design optimisation and validation’ activities of Tasks B1.5.1 and B1.5.2; correspondingly, the implications on the overall time-plan are not foreseen to be particularly significant even if this proves to be necessary.”
SP-B1 Response to Comment 1 and Deliverable DB1.11 During the Period M12-M24, a first assessment of the safety of the module was conducted and the results described in the 24-Month Periodic Report.
SP-B1 Response to Comment 1 and Deliverable DB1.11 • CRF Conclusions: • From the results of this analysis it can be stated that critical issues have not been encountered with respect to the EU-Homologation Directive. • In any case, even if some slight re-design of the overall layout will have to be considered following further analysis, it will form part of the normal activities of WP B1.5. • Correspondingly no additional time or costs are envisaged, • ie. the considerations made in response to the Review of the first 12 months remain valid.
SP-B1 Reviewers’ General Comments • Reviewers’ General Comments: • It may be said that a relevant amount of the planned activity has been completed and the outcomes are basically corresponding to the targets. • There are two points which still need a relevant effort by the involved partners: • 1. The safety issue of the integrated rear module needs to be assessed, in order to define the final design in due time for the construction/testing phase of the demonstrator vehicle. • 2. The CNG storage vessels need an implementation in order to fulfil the burst test in the area of bosses when dropped vertically on each dome, in order to avoid possible indentation in the case of rear side impact to the vehicle. • Of course, both problems are highly interrelated and the partners should work with tight collaboration.
SP-B1 Reviewers’ Specific Comments – Deliverable DB1.18 DB1.18: Vessel test programme of the advanced design Type IV The vessels constructed by XPERION were tested by WRUT, according to the rules on the matter. These included extreme temperature pressure cycling, hydrostatic pressure burst test, ambient temperature pressure cycling test, high temperature creep test, accelerated stress rupture test, impact damage test. All were fulfilled except those regarding the burst in the area of boss (vessels dropped in vertical position on each dome). This must be considered critical, directly dealing with the safety issue concerning the side impact of the integrated rear module. It is believed that a priority should be given to find a reliable solution to this problem.
SP-B1 Response to Comment 2 and Deliverable DB1.18 As documented in DB1.3, Xperion developed and produced Hybrid Vessels Gen 1.3, in 2010. 50 of these vessels were delivered for the advanced vessel tests at BAM and WRUT. Due the not entirely satisfactory results of the vertical drop tests within WRUT safety test programme, two general solutions were considered by Xperion to overcome this potentially critical safety issue: • 1. Additional shock protectors: • The ECE Regulation R110 accepts such a solution, if these elements become an integral part of the vessels. • Xperion applies shock protectors for type IV vessels used for CNG bulk transport.
SP-B1 Response to Comment 2 and Deliverable DB1.18 • In principle, this solution would also be feasible for an automotive application of the type targeted in INGAS. • Nevertheless, the protectors as additional components mean additional weight and volume and increasing vessels costs. • Thus Xperion efforts focused on achieving an intrinsic improvement in the design. • 2. Design modification • Xperion assessed again several design options, aiming to achieve an improved fixation of the metal boss within the composite laminate structure. • Finally, a design solution was identified, named Hybrid Vessels Gen 1.4, which is characterized by a slight modification of winding pattern within the dome sector compared to hybrid vessel Gen 1.3 • This solutions uses the same carbon/glass content and thus achieving the same gravimetric and volumetric storage density.
SP-B1 Response to Comment 2 and Deliverable DB1.18 • The new design results in a significantly improved embedding of the metal boss in the laminate structure: • Xperion Conclusions: • Subsequently, drop tests of these vessels Hybrid Gen 1.4 were performed at the Xperion facility under the supervision of the notified body (TÜV Rheinland). • This new generation of Hybrid Vessels Gen 1.4 has now passed successfully the drop tests in vertical direction, • An official approval document will now be provided by the TÜV stating the successful drop tests and added as an Appendix to the updated DB1.18 report. • Xperion thus considers this to be a sustainable solution of the critical safety issue.