Figure 12: Defining tension and compression
Transcription
Figure 12: Defining tension and compression
Tragwerksentwurf I – Structural Design I Figure 12: Defining tension and compression To define tension and compression, we look at the local equilibrium of a node in the defined reading direction and draw the respective polygon as a free-body-diagram (FBD). The fastest and easiest way is to do this parallel to the drawing of the force diagram. The direction of the array defines the 112 BEISPIEL IN EINZELNEN SCHRIT TEN art of load: Away from node: tension (usually red); towards the node: compression (usually blue). Once all elements are known, the resultant can be drawn to the form diagram.MIT LAGEPLAN UND KRÄFTEPLAN ARBEITEN F1 I II F2 s1 s3 s4 VII s10 F1 III s6 s2 s5 F3 F3 F1 s'1 s7 IV s'9 Druck Compression s'2 s'3 BV s8 s9 F2 Zug Tension s'4 F1 s'8 Nullstab Unstrained member s'5 s'6 V Lageplan (1 cm = 7 m) Form diagram (1cm=7m) ^ BH s'7 BV BH BV Lageplan mit Angabe der Beanspruchungsart Form diagram including type of force der Tragwerkselemente (1 cm = 7 m) (1cm=7m) Kräfteplan (1 cm = 2700 kN) Force diagram (1cm=2700kN) ^ Knoten Node IVIV =NC N5 N4 russi pDre o5=m Knoten Node III III ^ s6 F3 s5 N7 = Zug NN =Tension 6 6 rsuio cnk rDes s4 N7 s8 N 7 7 =C No Interpretation des Kräfteplans = Zug 4 NN =Tension 4 n Vorgehen zur Bestimmung von Zug und Druck N5 N8 m=p F3 s7 io rupcrekss NN8=8=CDom s7 cokn N6 F3 n VI F3 NN = 7 7=C oDmr purec sksi o BH s11 6. Bestimmen von Zug und Druck