Option 13

Task 3, 12, 21, 40, 49


Objective 3

Rods AB and CB are connected in a hinge on the axis of which there are two load as shown in Figure 1. Fixing rods at points A and C. hinge. Determine the forces in the rods. Scheme of loading rods in the problem and the numerical values \u200b\u200bof the forces and their options to take from Table. 2.

Table 2

Problem number number scheme, kN

KN

3 III 0,5 0,8


Target 12

Determine the support reactions doubly-supported beams (Figure 2). These take their version of Table 3.

TABLE 3

Problem number number scheme

N / M N N • m

12 2 2 15 40


Task 21

Shock-traction devices, piston rods and other elements of the rolling stock operating in tension and compression.

Steel beams stepped section is loaded by the force along its axis, as shown in Fig. 3.

Given:

a) Young´s modulus MPa;

b) the allowable stress in tension and compression of the steel bar;

c) numerical values, as well as cross-sectional areas of stages and for its embodiment taken from Table 5.

Required:

1) build diagrams of longitudinal forces and normal stress along the length of the beam;

2) determine the movement of the free end of the timber;

3) test the strength of the beam and to indicate how (in percent) timber underused or overused.

Table 4

Problem number number load circuit kN cross-sectional area A cm2

21 I December 23 0.8


Task 40

With torsion most often occur in the machine shaft (shaft generators, gearboxes, etc.).

Using the data of Figure 4 and Table 5 for steel shaft:

1) determine the values \u200b\u200bof moments,;

2) build epure torque;

3) find the dimensions of the cross section in two versions: a) approach; b) the ring of a predetermined ratio of the internal and external diameters. Compare weight of the boards of both calculation options. Take MPa.

Table 5

Problem number number scheme, kW

KW

KW

, Rad / s

40 X 52 14 June 40


Problem 49

For a given doubly-supported beams in the frame of the car body or platform (Figure 14) to determine the support reactions, build diagrams of transverse forces and bending moments and selected on the basis of strength required size of two I-beams, having to become 09G2D MPa. Data are taken from Table 6.

Table 6

Problem number number scheme, kN / m

KN

KN • m

IV 49 50 50 80