Cuaderno Resistencia De Materiales 1

REPASO DE ESTATICA













Para obtener RC

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Para obtener RAy

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Comprobando la RAy

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Para obtener Ty

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Para obtener RAy

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Para obtener RAx

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si Tx = RAx

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Para obtener la tensión

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DCL del nodo A

Para obtener TAD




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Para obtener TAC

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ESFUERZO AXIAL O NORMAL

E s la accion debida a una carg ya sea a tension o a compresion sobre un area determinada.

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DCL C

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DCL A

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DCL B

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De A

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De B

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De C

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[pic]Esfuerzo cortante

La carga es paralela a la seccion de corte




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APOYO SIMPLE

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APOYO DOBLE

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MAT DEL PERNO DEL TORNILLO

ASTM-325-GR1-15000 PSI

ASTM-325-GR2-17500 PSI



FALLA POR APLASTAMIENTO



[pic]in doble

[pic]insencillo

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Por aplastamiento

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Por tensión

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Ejemplo

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POR APLASTAMIENTO

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POR TENSION

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[pic]15” 1700 lb

4”





3”



3”







ASTM-325-GR1=16000

ASTM-325-GR2=17500

M=1700lb(15”)=25.500 lb-plg

TORNILLO 4 UTILIZADO PARA ANALIZAR

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[pic]+[pic]=288[pic]

CALCULO DEL TORNILLO

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PARA QUE LA SEPARACION DEL BARRENO AL CENTROIDE DEBE SER 2 VECES EL DIAMETRO DEL BARRENO, ASI ESTE SERA ADECUADO.

SEPARACION = 2[pic]

































Rx 500 lb [pic] [pic]

Ry [pic]

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2” [pic] [pic]

[pic]1.5”

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[pic] = [pic]

ESFUERZO POR TEMPERATURA. [pic]

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ESFUERZO TOTAL

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+ =



DEFORMACION POR CARGA

[pic] Sabiendo que P/A = σ [pic] = [pic]



DEFORMACION POR TEMPERATURA

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DEFORMACION TOTAL





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Tf = 84°

Ti = 200°Ma + ΔINO X [pic]

α = 17 X [pic] °C

Rx Ry E= 193gPa

δ = 7.86 x[pic] g/ [pic]

γ = 0.284 lb = 7.83 X [pic]Kg / [pic]

SECCION TRIANGULAR.



Area = [pic]= 150 [pic]



Vol = AH= (150) (30) = 4500 [pic]

w = γV = 7.8 X [pic] (4500) = 35.415 Kg

w = 347.42 N



∑Fy = 0

Ry - 347.42 + 1500 = 0

Ry = -1152.58 N



POR CARGA....