Andreas Schoissengeier

Automotive Engineering
Peirianneg Fodurol

Assessment and Optimization of a Lightweight Chassis.

Asesu ac Optimeiddio Ffrâm Ysgafn.

The aim of this report was to assess and optimize the chassis for an electric vehicle. The requirements for the chassis were to transport 3 people, to produces no local emissions, to have low weight and low costs. Based on the requirements stated, two existing design of a chassis were the base of the project. The rst design is based on a single central element and is manufactured from square tubes. The second design has a more complex geometry similar to a tube frame and uses round tubes. For the assessment, which is used to optimize the current designs, is based on a literature research. The assessment categories states the requirements for a good chassis. The structural requirements are the most important assessment factors, because those are the fundamentals for any further assessment. Sti ness, strength and safety are the structural requirements. The torsion and bending sti ness were tested via simulation in Autodesk fusion 360. For design 1, a torsion sti ness of 16 669 Nm/degree and for the second design a value of 98815 Nm/degree is resulting. The further assessment is focused on the chassis types and their advantages and limitations, he used materials, the element shape and their joining technology. Also, the safety with a focus on secondary safety was used for the assessment. For design 1, the simple geometry, the high bending sti ness and the modularity resulting from the clamps are the main advantages. The design was limited by the low torsion sti ness and the lack of safety elements. Design 2 had the main advantage due to the side structure. This structure increased the torsion sti ness and the secondary safety in case of a side impact. The main limitations were the complex geometry and the high manufacturing e ort. The advantages and limitations resulting from the assessment were used to develop an optimized version. The optimized version is based on design 1 and improved by adding elements of design 2. The design was reassessed and had shown increased torsion sti ness and secondary safety by keeping a simple geometry. Some of the joints were welded instead of clamped to reduce the extra weight and create sub-assemblies without losing the modularity.

Nod yr adroddiad hwn oedd asesu ac optimeiddio'r ffrâm ar gyfer cerbyd trydan. Y gofynion ar gyfer y ffrâm oedd cludo 3 o bobl, peidio cynhyrchu unrhyw allyriadau lleol, pwysau isel a chostau isel. Yn seiliedig ar y gofynion a nodwyd, sylfaen y prosiect oedd dau ddyluniad presennol o fframiau. Mae'r dyluniad _rst yn seiliedig ar un elfen ganolog ac mae'n cael ei weithgynhyrchu o diwbiau sgwâr. Mae geometreg yr ail ddyluniad yn fwy cymhleth tebyg i ffrâm tiwb ac mae’n defnyddio tiwbiau crwn. Ar gyfer yr asesiad, a ddefnyddir i optimeiddio'r dyluniadau presennol, mae'n seiliedig ar lenyddiaeth ymchwil. Mae'r categorïau asesu yn nodi'r gofynion ar gyfer ffrâm dda. Y gofynion strwythurol yw'r ffactorau asesu pwysicaf, oherwydd rheini yw’r hanfodion ar gyfer unrhyw asesiad pellach. Sythder, cryfder a diogelwch yw'r gofynion strwythurol. Profwyd y sythrwydd dirdro a phlygu drwy efelychu yn Autodesk fusion 360. Ar gyfer dyluniad 1, mae sythrwydd dirdro o 16 669 Nm/gradd ac ar gyfer yr ail ddyluniad mae gwerth o 98815 Nm/gradd yn deillio ohono. Mae'r asesiad pellach yn canolbwyntio ar y mathau o fframiau a'u manteision a'u cyfyngiadau, y deunyddiau a ddefnyddiwyd, siâp yr elfen a'r dechnoleg cysylltu. Hefyd, defnyddiwyd y diogelwch gyda ffocws ar ddiogelwch eilaidd ar gyfer yr asesiad. Ar gyfer dyluniad 1, y geometreg syml, y sythrwydd plygu uchel a'r modiwleiddio sy'n deillio o'r clampiau yw'r prif fanteision. Cyfyngwyd y dyluniad gan y sythrwydd dirdro isel a'r diffyg elfennau diogelwch. Dyluniad 2 oedd â'r brif fantais oherwydd y strwythur ochr. Cynyddodd y strwythur hwn sythrwydd y dirdro a'r diogelwch eilaidd mewn achos o sgil-effaith. Y prif gyfyngiadau oedd y geometreg gymhleth a'r ymdrech gweithgynhyrchu uchel. Defnyddiwyd y manteision a'r cyfyngiadau a ddeilliodd o'r asesiad i ddatblygu fersiwn optimaidd. Mae'r fersiwn optimaidd yn seiliedig ar ddyluniad 1 ac wedi’i wella drwy ychwanegu elfennau o ddyluniad 2. Ailaseswyd y dyluniad ac roedd wedi dangos mwy o sythrwydd dirdro a diogelwch eilaidd drwy gadw geometreg syml. Roedd rhai o'r cymalau wedi cael eu weldio yn lle eu clampio i leihau'r pwysau ychwanegol a chreu is-osodiadau heb golli'r modwlaredd.