4.4 鍠瓔鐭╁舰鎴潰鍙楀綆妲�(g貌u)浠舵鎴潰鍙楀綆鎵胯級鍔涜▓(j矛)绠�

4.4.1 鍩烘湰鍏紡鍙婂叾閬╃敤姊濅欢

1.鍩烘湰瑷�(j矛)绠楀叕寮�

鏍规摎(j霉)鍔涚殑骞宠　姊濅欢鍙婂姏鐭╁钩琛℃浠跺彲寰�

α1fcbx = Asfy (4-26)

M ≤fyAs(h0-x/2) (4-27)

鎴� M≤α1fcbx(h0-x/2) (4-28)

2. 閬╃敤姊濅欢

(1) ρ≤ ρb =α1ξbfc/fy (4-29a)

鎴� ξ≤ ξb (4-29b)

鎴� X ≤ξb ho (4-29c)

(2) ρ≥ρmin 鍗� As≥Asmin = ρminbh0 (4-30)

3. 鍠瓔鐭╁舰閬╃瓔姊佹壙鍙楃殑鏈€澶у綆鐭� Mumax

Mu锛宮ax=α1fcbh02·ξb(1-0.5ξb) (4-31)

4. 姊�銆佹澘鐨勭稉(j墨ng)婵�(j矛)閰嶇瓔鐜�

鏉� ρ=(0.3锝�0.8)%

鐭╁舰姊� ρ=(0.6锝�1.5)%

Τ褰㈡ ρ=(0.9锝�1.8)%

4.4.2 鎴潰鎵胯級鍔涜▓(j矛)绠楃殑鍏╅鍟�(w猫n)椤�

1. 鎴潰瑷�(sh猫)瑷�(j矛)

宸茬煡: b×h銆� fc銆� fy銆� M

姹�: As

鐢ㄥ熀鏈叕寮忚▓(j矛)绠楁椹燂細

(1) 鏌ラ檮琛�5-4寰楁贩鍑濆湡淇濊(h霉)灞ゆ渶灏忓帤搴

(2) 鍋囧畾 as

姊� as = c + 10mm (姊佸収(n猫i)鍏╁堡閶肩瓔鏅�(sh铆)as = 60mm)

鏉� as = c + 5mm

(3) ho = h - as

(4) 鐢� M≤α1fcbx(h0-x/2) —→ 姹� x

(5) 椹�(y脿n)绠楅仼鐢ㄦ浠�(1) x ≤ξbh0

鑻� x > ξbh0锛屽墖闇€鍔犲ぇ鎴潰锛屾垨鎻愰珮fc锛屾垨鏀圭敤闆欑瓔鎴潰銆�

(6) 鐢� α1fcbx=Asfy —→ 姹� As

(7) 閬搁厤閶肩瓔锛� As瀵�(sh铆) =(1 ± 5%)As

(8) 椹�(y脿n)绠楅仼鐢ㄦ浠�(2) ρ≥ρmin

鑻�ρ<ρmin锛� 鍓� As瀵�(sh铆) = Asmin = ρminbh

闄勮〃 4-1

2. 鎴潰寰�(f霉)鏍�

宸茬煡锛� b×h銆� fc銆� fy銆� As 銆�( M )

姹傦細 Mu ( 姣旇純 M ≤ Mu)

鏂规硶涓€锛�

(1) 瑷�(j矛)绠� ρ锛� ρ= As / bho

(2) 瑷�(j矛)绠� ξ锛� ξ= ρfy /α1fc

(3) 椹�(y脿n)绠楅仼鐢ㄦ浠讹細

鈶� 鑻� ξ ≤ξb 涓� ρ≥ρmin 锛� 鍓� Mu=α1fcbh02ξ(1-0.5ξ)

鈶� 鑻� ξ >ξb 鍙�ξ =ξb 锛� 鍓� Mu=α1fcbh02ξb(1-0.5ξb)

鈶� 鑻� ρ <ρmin 鍙� ρ=ρmin锛� 鍓� Mu= 0.292 bh02ft

(4) 鐣�(d膩ng) Mu≥M 鏅�(sh铆)锛屾豢瓒宠姹�;鍚﹀墖鐐轰笉瀹夊叏銆�

鐣�(d膩ng) Mu 澶т簬 M 閬�(gu貌)澶氭檪(sh铆)锛岃┎鎴潰瑷�(sh猫)瑷�(j矛)涓嶇稉(j墨ng)婵�(j矛)銆�

鏂规硶浜岋細

(1) 瑷�(j矛)绠� ρ锛� ρ= As / bho

(2) 瑷�(j矛)绠� x锛� 鐢�α1fcbx = fy As —→ 姹� x

(3) 椹�(y脿n)绠楅仼鐢ㄦ浠讹細

鈶� 鑻� x ≤ξbh0 涓� ρ≥ρmin 锛� 鍓� Mu=α1fcbx(h0-x/2)

鈶� 鑻� x > ξbh0 鍙� ξ =ξb 锛� 鍓� Mu=α1fcbh02ξb(1-0.5ξb)

鈶� 鑻� ρ <ρmin 鍙� ρ=ρmin锛� 鍓� Mu= 0.292 bh02ft

(4) 鐣�(d膩ng) Mu≥M 鏅�(sh铆)锛屾豢瓒宠姹�;鍚﹀墖鐐轰笉瀹夊叏銆�

鐣�(d膩ng) Mu 澶т簬 M 閬�(gu貌)澶氭檪(sh铆)锛岃┎鎴潰瑷�(sh猫)瑷�(j矛)涓嶇稉(j墨ng)婵�(j矛)銆�

娉ㄦ剰锛氬湪娣峰嚌鍦熺祼(ji茅)妲�(g貌u)瑷�(sh猫)瑷�(j矛)涓�锛屽嚒鏄鎴潰鎵胯級鍔涘京(f霉)鏍搁锛岄兘蹇呴爤姹傚嚭娣峰嚌鍦熷彈澹撳崁(q奴)楂樺害 x 鍊�

4.4.3 姝ｆ埅闈㈠彈褰庢壙杓夊姏鐨勮▓(j矛)绠楃郴鏁�(sh霉)鑸囪▓(j矛)绠楁柟娉�

1.瑷�(j矛)绠楃郴鏁�(sh霉)

(1)αs —— 鎴潰鎶垫姉鐭╃郴鏁�(sh霉)

M=α1fcbh02ξ(1-0.5ξ)

浠� αs=ξ(1-0.5ξ)

鍓� αs=M/α1 fcbh02

(2)ξ —— 鐩稿皪(du矛)鍙楀鍗€(q奴)楂樺害ξ= x/ho

αs=ξ(1-0.5ξ)

鍓� ξ= 1-(1-2αs)1/2

(3)γs —— 鍏�(n猫i)鍔涚煩鐨勫姏鑷傜郴鏁�(sh霉)γs = z/ho

γs = 1-0.5ξ

鍓� γs=[1+(1-2αs)1/2]/2

2. 瑷�(j矛)绠楁柟娉�

(1) 姹�αs

αs=M/α1 fcbh02

(2) 姹�ξ銆�γs

ξ= 1-(1-2αs)1/2

γs=[1+(1-2αs)1/2]/2

(3) 椹�(y脿n)绠楅仼鐢ㄦ浠�(1) ξ ≤ξb

鑻� ξ > ξb锛屽墖闇€鍔犲ぇ鎴潰锛屾垨鎻愰珮fc锛屾垨鏀圭敤闆欑瓔鎴潰銆�

(4) 鐢� M= fyAsγs h0 —→ 姹� As

鎴栫敱 α1fcbξh0=Asfy —→ 姹� As

(5) 閬搁厤閶肩瓔

As瀵�(sh铆) =(1 ± 5%)As

(6) 椹�(y脿n)绠楅仼鐢ㄦ浠�(2) ρ≥ρmin

鑻�ρ<ρmin锛� 鍓� As瀵�(sh铆) = Asmin = ρminbh