¥­¿Å »P ¼u©Ê

 

 

¥­¿Å (Equilibrium)

¥­¿Å

(°Ê¶q) P = ±`¼Æ¡B(¨¤°Ê¶q) L = ±`¼Æ

 

ÀRºA (static) ¥­¿Å

P = 0¡BL = 0

 

í©wÀRºA¥­¿Å

¤pÂZ°Ê«á¯à¦^´_¨ì¥­¿Å¦ì¸m

 

¤£Ã­©wÀRºA¥­¿Å

¤pÂZ°Ê¯à±N¥­¿Å¥Ë¸Ñ

 

ÀRºA¥­¿Å¤ÀªR

¦b¤uµ{¤W¬O«Ü­«­nªº

 

 

 

°ÊºA¥­¿Å

¨£½Ò¥»¨Ò Segway

 

 

 

 

¥­¿Åªº±ø¥ó

¤Oªº¥­¿Å

Fnet = 0

 

¤O¯xªº¥­¿Å

τnet = 0

 

­Y¬OÀRºA¥­¿Å¡A«hÁÙ¨ì¦A¥[¤W

½u°Ê¶q¬°¹s

P = 0

 

µ²ºcªºÃ­©w©Ê

í©w©Êªº©w¶q±ø¥ó

±q¤O»P¦ì¯àªºÃö«Y¥Xµo¡A¤O¥i¥H¥½¦Û¦ì¯à¹ï¦ì¸m¤@¦¸·L¤À¡A¬G¤O¹ï¦ì¸mªºÅܤƴN¨Ó¦Û¦ì¯à¹ï¦ì¸mªº¤G¦¸·L¤À¡C

Case 1. í©w¥­¿Å

d2 U/dx2 > 0 

(¦V¤W¶} ©ßª«½u)

Case 2. ¤£Ã­©w¥­¿Å

d2 U/dx2 < 0

(¦V¤W¶} ©ßª«½u)

Case 3. ¦ÛµM¥­¿Å

d2 U/dx2 = 0

(¥­©Zª½½u)

 

 

­«¤ß

­«¤ßªº©w¸q

§@¥Î©ó¬Y­Óª«Å骺­«¤O Fg¡A¬Oµ¥®Ä©ó§@¥Î©ó³æ¿W¤@­ÓÂI¡A¦¹ÂIºÙ¬°ª«Å骺­«¤ß (Center of Gravity, cog)

³oùتºµ¥®Ä¬O«ü­ì¥»²Õ¦¨¤¸¯À¤Wªº¨ü¤O§ï²¾¨ì­«¤ß¡A«h­ìª«Åé¤]¤£·|¦³Á`¦X¤O»P¦X¤O¯xªº¤£¦P¡A§Yª«Å骺ª¬ºA¤£ÅÜ¡C

 

­«¤ß»P½è¤ß­«¦Xªº±ø¥ó

¥ý¨M±ø¥ó¬O­«¤O³õ§¡¤Ã¡]¤§«eÁ¿¹L¤F¡^¡AÃÒ©ú¨£½Ò¥»¡A¦Û¤v¬Ý

 

§ä­«¤ßªº¤èªk

¤@¡B¦Q÷ªk¡]¬°¤°»ò·| work ? ¡^

¤G¡B¨â«ü²¾ªñªk¡]¬°¤°»ò·| work ? ¡^

 

 

ÀRºA¥­¿Åªº¤@¨t¦CÃD¨Ò

Bauer

11.1¡]¹Ï 11.6¡^¼¼ªO

¡]¥i¦Û¦æ¸Õ¤£¦Pªº°²·Q¶b¤ßÂI¡^

11.2 ¡]¹Ï 11.7¡^Á|°×¹aªº¤GÀY¦Ù¨ü¤O

11-3  ¡]¹Ï 11.8¡^Å|¤ì¶ô¡]³Ì¦h¦ù¦h»·¥X¥h¡H¡^

¤U¹Ï¬O¯uªºÁÙ¬O°²ªº¡H

SP 11.1¡]¹Ï 11.9,10¡^ÀJ¶ìÂ\©ñ¡]·|¤£·|­Ë¡H¡^

11.4 ¡]¹Ï 11.12¡^±è¤W¯¸¤H¡]¦a¤£¯à¤Ó·Æ¡^

 

½Ò¥»µ¹¤j®a´£¥Ü¸ÑÃD§Þ¥©¡A

 

 

Halliday

12-1¡]¹Ï 12-4¡^ ¨â¯¯¼µ¤@¼Ù

12-2¡]¹Ï 12-5¡^±è¤l±Ï¤õ­û

12-3 ¡]¹Ï 12-6¡^¿û¯Á»P¦³Âà¶b¤§¦Q±ì

12-4 ¡]¹Ï 12-7¡^¤ñÂı׶ð

½Ò¥»µ¹¤j®a¦C¥X¸ÑÃD§Þ¥©¾ã²z¡A¦@¤EÂI¡A¥i¥H¬Ý¤@¤U¡C

¤ñ¸ûÃöÁ䪺¬O¡G

¡]¤@¡^µe¥X¤O¹Ï¡A¬I¤OÂI»P¤è¦V¬Ò­n©ú¥Ü

¡]¤G¡^¼g¤U¤ô¥­»P««ª½¤O¤§²b¤O¬°¹sªº¤èµ{¦¡

¡]¤T¡^¿ï¤@­Ó¬I¤OÂI§@¬°¤O¯x¤èµ{¦¡ªºÂà¶b¤¤¤ß

 

°Q½×

¤@¡B¨«¿û¯Áªíºt¯S§Þªº¤H¡A¦³®³ªøªøªº¥­¿Å±ì»P¨S®³¨ì©³®t¦b¨ºùØ¡H

¤G¡B³æ¤ùªº±è¤l¬O­«ªºÁÙ¬O»´ªºÃ­¡HÁÙ¬O¨S®t¡H

 

 

 

 

¥¼©wµ²ºc ( Indeterminate Structures)

¥¼ª¾¼Æªº­Ó¼Æ¤ñ¤èµ{¦¡ªº±ø¥ó§ó¦h¡AºÙ¬°¬O "¤£½T©wªº" (indeterminate)¡C

¨Ò¦p¡A§Ú­Ì³oùئ³¤T±ø¤èµ{¦¡¥i¥Î¡]¥­­±§@¹Ï¯à³B²zªº°ÝÃD¡A¦³ x¡By ¤À¶qªº²b¤O³£¬°¹s¡A¥H¤Îª«¥ó¤£¨ü²b¤O¯x¡A¦@¤T­Ó±ø¥ó¡^¡A¦pªG¦³¥|­Ó¥¼ª¾ªº¤O©Î¤O¯x«Ý¨D¸Ñ¡]¦p¥|­Ó®à¸}ªº¨ü¤O¡^¡A´N·|Åܦ¨ indeterminate °ÝÃD¡]¤T­Ó¸}ªº®à¤l¤Ï¦Ó¥i¸Ñ¡^¡C

µM¦Ó¡A¯u¹ê¥@¬É¤¤³o¨Ç¨t²ÎÁ`¬O¦³¬Y­Ó¤O¦s¦b¡A¨º¨ì©³¥»¸`ªº¤èªk¤¤¬O¤Ö¤F¤°»ò¡H³o­Ó°ÝÃDªºµª®×¬O¡A§Ú­Ì¤@¶}©l´N§âª«Åé°²³]¦¨¬O­èÅé¡A¨S¦³µ·²@§ÎÅÜ¥i¯à¤Î¼u©Êªº¡C

½Ò¥»´£¨ì¡A¤£Ã­ªº¥|¸}À\®à¡A§Ú­Ì±`·|§ä­Ó¯È§é¤@§é¨Ó¹Ô¡C¦pªG¬O¤@ÀY¤j¶H¨Ó§¤¦b®à­±¤W¡A¦b®à¤l¨S³Q§¤«±ªº±¡ªp¤U¡A§Ú­Ì¥i¥H·Q¹³¥|¤ä¸}³£¬Oµ²¹êµÛ¦aªº¡A¦]¬°®à­±¦ÛµM·|§ÎÅܨӦ]À³¡C

­n¸Ñ¨M³o­Ó "¤£½T©w©Ê" °ÝÃDªº¨D¸Ñ¡A´N­n¤Þ¤J¹ïª«Åé "¼u©Ê (elasticity)" ªº±´°Q¡C

 

¨ÒÃD¡G12-6 ¤T¸}¼µ¦aªº¥|¸}®à

 

 

¬ì¾Çª±¨ã¡GTheo Jansen ªº ¥é¥ÍÃ~

¾Ç¬ã ¤j¤Hªºª±¨ã http://www.youtube.com/watch?feature=endscreen&NR=1&v=qAVv0uM0UvI

http://www.ted.com/talks/theo_jansen_creates_new_creatures.html

http://www.youtube.com/watch?v=WcR7U2tuNoY

 

 

 

Bauer ½Ò¥»¤§¯Z¯Å ¤U¬q¸õ¹L

 

¼u©Ê (Elastisity)

¤Z¬Oª«½è¥²¦³¼u©Ê¡]¨ü¤O¥²§ÎÅÜ¡^¡A±q·LÆ[¨¤«×¦Ó¨¥¡Aª«½è¥Ñ­ì¤lºc¦¨¡A¦Ó­ì¤l¤§¶¡¦³¼u®¬Û³s¬O¤@­Ó±`¨£ªº¼Ò«¬¡C¦]¦¹§Ú­Ì¤£¥²·N¥~¤Z¬O´NÀ³¸Ó·|¦³§ÎÅÜ¡C

 

À³¤O (Stress)

¨C³æ¦ì­±¿nªº§ÎÅܤO

 

À³ÅÜ (Strain)

³æ¦ì§ÎÅÜ

À³¤O = ¼Ò¼Æ × À³ÅÜ

 

±`¨£ªº¤TºØÀ³¤OÀ³ÅÜ

±iÀ³¤O¡B°ÅÀ³¤O¡B¬yÅéÀ³¤O¡A¨£½Ò¥»¹Ï 12-10¡C

 

¼u©Ê¡]½u©Ê¡^¡BÅܧΨìÂ_µõ

¹Ï 12-12 Åã¥Ü¤F À³¤O¡ÐÀ³Åܦ±½u ( stress-starin curve )

¤j©ó ­°¥ñ±j«× (yield strength) Sy ¤§«á¡A·|³y¦¨¥Ã¤[ÅܧΡA¨£ªí 12-1

¤j©ó ·¥­­±j«× (ultimate strength) Sr ¤§«á¡A·|³y¦¨Â_µõ¡A¨£ªí 12-1

 

±iÀ³¤O (tensile stress) ©Î À£ÁYÀ³¤O (compressive stress)

F / A = E (ΔL / L )

¨ä¼Ò¼Æ E ¥s·¨¤ó«Y¼Æ (Young's modulus) ¡A¨£ªí 12-1

ΔL / L ¥i¥H¥Î strain gage ¨Ó¶q¡A¨£¹Ï 12-13

 

°ÅÀ³¤O

F / A = G (Δx / L)

G ¬O °Å¤O¼Ò¼Æ (shear modulus)

 

¬yÅéÀ³¤O (Hydraulic stress)

§YÀ£¤O

p = B (ΔV / V)

B ¬O ¶ôÅé¼Ò¶q (Bulk modulus)