FAQ >> Crane Steel Structures Test Problems

Crane Steel Structures Test Problems

Currently, the steel plant are widely used in plant construction. Because of its short construction period, construction process is relatively simple, low cost and other advantages, except for some special occasions, the steel plant is always given priority. And installation of the cranes in the reinforced concrete test different plant, steel plant cranes within the test several more should pay attention to the problem. 1 vibration, noise sound, easy to loose connection Vibration absorption effect of the difference between steel plant, crane operation, especially when the carts will have a greater running vibration and noise. The vibration method is currently used in the crane rail on the beam orbit and bearing pad into the rubber gasket ramp. The rubber gasket can be noise absorber, but also adjust the level of the cart track the level of degree. However, the structure reduces the cart track and Heritage Rail Beam asked joint stiffness. In the crane operation, the rubber gasket compression and rebound asked rested cart track lead connection (such as rail connection plate, hook bolts, etc.) more loose. In the test, the number of times that the cart track or tracks between the hook bolts loose bolts loose. It is therefore recommended to take the following measures rail mounting: (1) strictly control the rubber gasket height difference between high and low beams in the order of tracks is large, you should use iron leveling pads, and finally rubber mat; (2) bend using a larger hook bolt preload, compression rubber gasket, increasing the joint stiffness, and torque wrench should be used evenly distributed between the rail mounting bolts preload; (3) using double nuts and other more reliable anti-solid tillage. 2 Transverse rail bearing stiffness and instability Steel plant bearing rail beam, the use of "work"-shaped self-contained surface of steel, bearing a fixed common rail beam itself, as follows: bearing rail mounted on a steel beam column bracket on the edge of plate under the beam with bolts and bracket connection, edge of the beam and column connection plate through the connecting plate. When the crane car running or hanging objects swinging along the longitudinal girder, its tracks by the big wheel bearing beams to exert a lateral change of load; at this time if the commitment is not enough lateral stiffness of rail beams severe vibration occurs, or is not firmly fixed bearing track beam and instability, the safe operation of cranes will bring adverse effects. For some bearing rail span beam, when the crane rail beam under in the bearing, the load the car, the brake will cause the beams have a greater bearing rail lateral vibration. Current crane inspection regulations Chengdui Cheng Transverse stiffness of rail no clear standards and corresponding test methods, making the test to determine the time of difficulties. No-load tests can be recommended, the amount of 1.1 times the amount of load and load conditions to verify the simple commitment from the rail car brake beam lateral stiffness. 3 crane girder stiffness measurement Distinguishing the main beam stiffness method traditionally used water level in the main suspension span beam scale, ruler, hanging under the pretension weight, were measured with the water level in the no-load and cross the main beam in the corresponding rated load of tape reading, calculated the value of the main beam to determine the elastic deflection stiffness of the main beam is qualified. In fact, the amount set under the main beam in the reading, both the actual elastic deformation of the main beam, as well as bearing rail beams, wagon wheel assembly space, car assembly asked the gap, cart tracks and car track deformation, deformation of the lifting rope and so on. Plant installed in the concrete structure for the crane, the elastic deformation of the main beam than the previous several other large and more space and orbital assembly deformation is negligible; but for steel plant in the crane, the bearing beam in its tracks the amount of wheel load reduction will have greater flexibility in deflection (measured about 2 ~ 3 mm), will accumulate to Crane girder deformation measurement value, resulting in large errors. Therefore, the value measured using traditional methods near or beyond the critical value of the S/800 Time (S for the crane span), especially for long span beams coat bearing a small span of crane rail occasion, should consider the bearing rail elastic deflection of beam . The following methods can be used and then measured again to verify: 2 at end of the crane beam across the inside and the main beam to hang three rulers, weights were used to pretension, a crane with a water level were measured and the amount set out in the no-load 3 under the scale readings, and calculate the actual amount of flexibility in the main beam under the load deflection value, l = H a (H1 + Day 2) / 2. Where the day, H1, respectively, in the main beam under the left side and right side beam scale beam load and the amount set out in the next reading difference. Above the track beams and the bearing deformation of the cart wheels are reflected in the end beam of the numerical scale changes, the basic commitment to eliminate the rail beams on the Determination of the main beam stiffness, higher accuracy.

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