Unless grip them for pull tests. Figure 4­1:

Unless like other materials carbon fiber is difficult and expensive to recycle and once the part is damaged it`s difficult to rework the part, possibly the entire part should be replaced. The main disadvantage of carbon fiber is that it does not yield but rather shatters when loads greater than it can handle are applied to it. While most carbon fiber tubes are really strong in tension, they are not as strong in compression and that can sometimes be a disadvantage. The standards of carbon fiber tubes are not prescribed as the way we have it for aluminum or steel. So, it’s quite difficult to have the standard dimension from the manufacturers. A pultruded tube from one manufacturer may have significantly different properties from another manufacturer, and same goes with roll?wrapped tubes. Carbon fiber bonds with other material by the gluing process, so, skilled labor required to handle the entire process.4.0 Mechanical Design    4.1 Size of the TubeSince in this project we are focusing only implementing carbon fiber tubes on suspension system, based on our previous calculations on suspension geometry and the dynamic behavior of the suspension system we are slightly modifying the dimensions of the existing geometry system. Even though we need to use aluminum inserts at the end of the eye-rod which connects the upright assembly the aluminum inserts are modified according to the old PGR-17 car calculations. It also concerns the dimension rules of FSAE Europe and the performance were using customized 0.75 inch outer diameter carbon fiber tubes.     4.2 Aluminum as connectorsThe aluminum connectors are the most important part in this report. It connects the carbon fiber from the swing arm and connects to the upright assembly of A-arm. The entire force is acting will be acting in the suspension like bounce, jounce and the ride comfort of the car. The aluminum connectors are designed in such a way to withstand all the forces and loads. The design of the aluminum connectors. For testing purposes, inserts like the one shown below in figure 4?1 on the left were used. These inserts were designed with an extended shoulder length so that an Instron machine can grip them for pull tests. Figure 4­1: Insert used for experiments (left) and actual A­arm insert (right)The experimental inserts were also machined out of aluminum alloy 6061?T6 because of its low cost. It is important to note that Al 6061?T6 was just used for testing, whereas in the actual suspension design, aluminum 2024 or 7075 alloys are recommended because of their higher strengths.     4.3 ?lum?n?um ?t?h?ng ?r??????n?ly??? ?n d?ff?r?nt ?t?h?ng k?t? w?? n?t ??rf?rm?d but thr?ugh ??m? r????r?h, ?t w?? d?t?rm?n?d th?t ?t?h?ng ?lum?num ?nd ???t?ng ?t w?th ?l?d?n? ?? ? g??d ??t??n. Th? b?n?f?t? ?f ?n ?l?d?n? ???t?ng ?r? th?t ?t ?r?v?nt? ??rr????n, ?nd ?l?? m?k?? th? ?dh???v? b?nd t? th? ?lum?num ?tr?ng?r. F?r th??? t??t?, th? W??t ?y?t?m 860 ?lum?num ?t?h?ng K?t w?? u??d. ?t ?? ? 2???rt ?t?h?ng k?t th?t ??m?? w?th ? ?l??r???l?r?d ?l??n?r ?nd ? g?ld?n???l?r?d ?l?d?n? ??lut??n ?? ?h?wn ?n f?gur? 4?2 b?l?w.F?gur? 4­2: W??t ?y?t?m ?lum?num ?t?h?ng ?nd ?l?d?n? ???t?ng k?t Th?r? ?r? ?l?? ?th?r ?lum?num ?t?h?ng ?r?du?t? l?k? th? Du??nt ???d ?t?h ?nd ?l?d?n? ??lut??n?, but ?ny ?lum?num ?t?h?ng k?t w?ll d?. ?????f?? d?r??t??n? ?n h?w t? ?r???rly ?t?h ?nd ???t th? ?lum?num ?r? ?n ???t??n 5.1 ?f th?? r???rt.    4.4 B?nd G?? ??z? ?nd B?nd L?ngthTh? b?nd g?? b?tw??n th? ?lum?num ?n??rt? ?nd th? ??rb?n f?b?r tub? ?? ?n? ?f th? m??t ?r?t???l ??rt? ?f th? ??rb?n f?b?r ?u???n???n d???gn. R????r?h ?nd ?x??r?m?nt?t??n ?ugg??t? ? b?nd g?? ?f 0.004″ ? 0.012″ f?r h?t b?nd?ng, wh??h ?? wh?n th? ?dh???v? ?? h??t?d t? ?ur? f??t?r. F?r ??ld b?nd?ng, wh?n th? ?????m?n ?? ?ll?w?d t? ?ur? w?th?ut ?ny ?xt?rn?l h??t?ng, ? b?nd g?? ?f 0.008″ ?? r???mm?nd?d. Th??r?t???lly th? ?n??rt ?nd ??rb?n f?b?r tub? b?th n??d t? b? ?l?ghtly t???r?d ?n ?? th?t th? ?h??r ?tr??? ?n th? ???xy und?r t?n???n ?? ???t??lly ??n?t?nt, but ?x??r?m?nt? w?r? n?t ??rf?rm?d t? ??nf?rm th??.  F?gur? 4?3 b?l?w ?h?w? th? ?ff??t? th?t t???r?ng th? ?n??rt? ?nd tub?? h?v? ?n th? ?dh???v?.F?gur? 4­3: F?gur? ?h?w?ng th? ?ff??t ?f ? t???r?d tub?/?n??rt d???gn?x??r?m?nt? w?r? ?l?? ??rf?rm?d ?n ? ????r wr?tt?n ?n 2004 ?n th? ?ff??t ?f b?nd ??r?umf?r?n?? ?nd b?nd l?ngth ?f ?n??rt? ?nd ?t w?? ?h?wn th?t b?nd ???l?? l?n??rly w?th b?nd ??r?umf?r?n?? ?nd ???r???h?? ?n ??ym?t?t? w?th b?nd ?tr?ngth l?ngth. Th?? ?? kn?wn ?? th? V?lk?r??n th??ry, wh??h h?ld? tru? f?r b?nd?ng fl?t ?urf???? t?g?th?r, but th? ?x??r?m?nt? ??rf?rm?d ?n th? 2004 ????r ?r?v?d th?t th? ??m? ??n???t ?? ?l?? tru? f?r ?yl?ndr???l g??m?tr???.     4.5 B?nd G?? ?dh???v?L?k? ?ll ?th?r ??r?m?t?r? ?n ?yl?ndr???l b?nd?ng, th? r?ght ?dh???v? mu?t b? ?r???rly ?h???n f?r th? r?ght j?b. ?n ?n ?d??l b?nd, th? ?dh???v? b?nd? t?ghtly t? th? ?lum?num ?nd ??rb?n tub? ?urf????, ?nd wh?n th? fr??tur? h????n? ?t g??? thr?ugh th? ?dh???v? r?th?r th?n d?t??h?ng fr?m th? ?lum?num ?r tub? ?urf????. Th? ??rr??t w?y t? h?v? th?t f??lur? ?? thr?ugh ?urf??? ?r???r?t??n ?f th? ?lum?num ?nd ??rb?n ?urf????. ? h?gh ?h??r ?tr?ngth ?dh???v? ?? r?qu?r?d f?r ? ?tr?ng b?nd. ?n ? ????r r?l????d by L??t?t? ?ndu?tr??l ?dh???v??, ? ??m??r???n ?f d?ff?r?nt ty??? ?f ?dh???v?? ?n?lud?ng ??ryl?? b???d, ur?th?n? b???d, MM?, ?nd ???xy w?? d?n? ?nd ???xy ?h?w? t? h?v? th? t?ugh??t ?tr?ngth ?ut ?f ?ll th? ?dh???v??. F?r th? ?ur????? ?f th??? ?x??r?m?nt? th? ?dh???v? u??d w?? L??t?t? Hy??l ??120H?. ?t ?? ? h?gh ?tr?ngth 24 h?ur ?ur?ng ???xy, ?h?wn ?n f?gur? 4?4 ?n th? f?ll?w?ng ??g?. F?gur? 4­4: L??t?t? h?gh ?tr?ngth ???xy u??d f?r ?ull t??t ?x??r?m?nt?    4.6 Tub?­t?­U?r?ght ?tt??hm?nt?F?gur? 4­5: ?­?rm t? u?r?ght ?tt??hm?nt ?n ?GR 2017 ??r?n ? ??rb?n f?b?r ?u???n???n d???gn th? tub??t??u?r?ght ?tt??hm?nt? w?uld b? m?d? ?f h?gh ?tr?ngth 2024 ?r 7075 ?lum?num ?ll?y?. N? ?n?ly??? w?? ??rf?rm?d ?n th??? ??m??n?nt? ?f ? ??rb?n f?b?r ?u???n???n but th? ??m? ?x??r?m?nt? ?nd d?t? ?n th? T??t?ng ?nd R??ult? ???t??n ?f th??