ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
Specimens: MR24 roof panel 1.5 m purlin distance 0.5 mm plate thickness bracket thickness 08mm self-machine will air into the airtight airbag at a predetermined standard rate, air intake and speed personnel through the barometer to read the current pressure in the airbag. When the pressure reaches the first value of the preset test, the pressure is continued for one minute, and the number of destroyed rings is recorded. The shape of the deformed ring is repeated until the deformation of the sheet occurs, including local buckling of the sheet, overall collapse of the sheet, deformation of the sheet exceeding the specifications, and the sheet starts from the test of the bracket on the MR24 sheet. The displacement gauge is all located in the center of the plate. When the plate is loaded step by step, the deflection increases rapidly. At 5KPa, the displacement reaches 50mm, but the bite is intact. So the displacement gauge is placed at the joint of 360 degree bite. When the plate is loaded to 2.2KPa, the mid-span deflection of the rib is obviously beyond the specification. In other words, it has reached the set failure mode.
(See Figure 18.104.22.168 for the FM Certification Testing Industry and Company of the United States, one of the largest industrial and commercial insurance companies in the world, which provides testing and certification services to industrial products through its FM Approvals affiliated institutions. The certificate of FM certification is widely recognized worldwide, and the guarantee of FM Global Company is more inclined to use products that have passed FM certification. It shows consumers that the products or services have passed the highest standards in the United States and the world. Jia not only can satisfy consumers'requirements for product quality, but also can improve the location of products in the market and test reports. It is universally acknowledged that the "FM" recognition mark is also the symbol of the highest quality standard in consumers' minds. Its recognition mark surpasses the value of the certification itself, FM roofing system certification in the whole world. With the help of China Building Waterproofing Association, Suzhou Waterproofing Research Institute and FM Certification Company have successfully built the first single-layer windproof uncovering Laboratory for roofing of coiled timber which meets the technical requirements of FM Certification Company. Metal roof anti-wind exposure laboratory, authorized by FM certification company, will carry out external testing items standard FM ANSI/FM4471:2010 FM4471 "Grade 1 flat roof certification" describes the test standards of roof system in fire prevention, wind resistance, ice resistance, leakage prevention and other aspects. The main test content of this test is Butler's production of MR24 roof panels. Butler MR-24 roof slab is selected as the installation panel for the wind-suction resistant parts and specimens. It is 0.6 mm thick and its yield strength is not less than 345 MPa.
Purlin is a Z200 pre-middle hole purlin produced by Butler (Shanghai) Co., Ltd. with a thickness of 1.95 mm, yield strength of no less than 345 MPa and purlin spacing of 1.5 mm. The test platform and metal plate specimens are shown in Fig. 3. Butler scrubolt (r) self-drilling screw, ITM Buildex 12-24x |-1/4 "TEXS/5 self-drilling screw produced by IW Group Illinois Construction Products (Suzhou) Co., Ltd., and low-type connector of MR-24 roof panel made by Butler-wide-type lock sheet [see Fig. 3-12). Firstly, Z-type lining is passed through ITW T. EKS/5 self-drilling screw is fixed to the main model of the test stand, then the wide locking plate is fixed to Z-type purlin by using Butler scrubolt (r) self-tapping screw. The MR24 roof panel is laid on the test stand and clamped by the wide locking plate. Finally, the MR24 roof panel is clamped with the wide locking plate by the edge-winding machine.
The plane layout of the specimens is shown in Figure 3-13. The experimental process and damage of the specimens are shown in Figure 3-143.3. Data statistics and results analysis are raised to 4.3KPa (90PSF). During the process, the low-type connector-wide locking plate of MR-24 roof panel is pulled out from the metal plate lock seam, reaching the predetermined breaking condition, and reaching the wind-resistant uncovering grade of 3.6KPa (75PSF) occlusive roof panel in wind suction. Lower bearing capacity and deformation are mainly affected by the following factors: 4.1 plate type, support type and biting method. Combining with wind exposure test of Jiaochi II plate type in Zhongye Smelter, it can be seen that MR24 plate roof panel with mechanical bite has higher hand-load and ultimate deformation than Jiaochi III plate roof panel with manual bite, and its failure form is local plate. The stiffness and construction quality of buckling frame have a great influence on the performance of undercut connection slab under wind suction. The failure mode of undercut connection slab mainly occurs in 4.2 purlin spacing undercut connection roof slab at weak support. Under the action of wind suction, the bearing capacity and ultimate deformation of undercut connection slab gradually deteriorate with the increase of purlin spacing.
4.3 Construction quality and surrounding national measures.