Apparatus and methods of precast architectural panel connections

Abstract

Architectural precast concrete construction relies on mechanical connectors at discrete locations that may be damaged in a blast or seismic event, posing specific design problems to the engineer. These problems can be overcome with proper detailing. The performance of precast concrete cladding wall panel connection details may be enhanced by incorporating a specific connection hardware, herein described, that deforms elastically or inelastically to accommodate relative displacements due to building motion and/or energy associated with blast pressures.

Claims

1. An impact absorbing apparatus for use with a precast architectural panel comprising: a crushing tube, the crushing tube further comprising: a hollow tube like structure with a rectangular cross section, an approximately flat planar first face, an approximately flat planar second face, and an approximately centralized aperture having an inward entry point on the first face in alignment with an outward entry point on the second face, wherein the first face oppositely disposed and parallel to the second face of the crushing tube and wherein the second face having a higher crush resistance than the first face; wherein, the aperture adapted to receive a threaded rod, the threaded rod connected to the architectural panel via an embedded U-shaped bar; a coil spring through which the threaded rod is inserted, wherein the coil spring compresses during an impact; a bracket connected to the crushing tube via the threaded rod; a pair of adjusting nuts on the threaded rod; and, a bearing connection between each floor of a multistory building, the bearing connection connected to the bracket, wherein the architectural panel is mounted one panel per floor.

2. The apparatus as set forth in claim 1 wherein the crushing tube has a width ranging between 3.8 inches to 8.2 inches, a depth ranging between 1.8 inches to 4.2 inches, and a length ranging between 3.8 to 12.2 inches.

3. The apparatus as set forth in claim 1 wherein the threaded rod has a diameter ranging between 0.6 inches to 1.3 inches.

4. The apparatus as set forth in claim 1, wherein the impact is transmitted in a lateral direction to the bracket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view assembly drawing.

(2) FIG. 2 is a close-up view of the components surrounding a crushing tube and a coil spring.

(3) FIG. 3 is a close-up view of the effect on the crushing tube when relative force of an architectural panel exceeds a predetermined amount in an inward direction.

(4) FIGS. 4A and 4B is a close-up view of the effect on the crushing tube when relative force of the architectural panel exceeds a predetermined amount in an outward direction.

(5) FIGS. 5 and 5A is a close-up view of the crushing tube.

(6) FIG. 6 is an installed view of the crushing member.

(7) FIG. 7 is a graphical representation of variation of load with respect to displacement for a 8″ inch crushing tube.

(8) FIG. 8 is a graphical representation of variation of load with respect to displacement for a 8.5″ inch crushing tube.

(9) FIG. 9 is a graphical representation of variation of load with respect to displacement for a 9.0″ inch crushing tube.

(10) FIG. 10 is a graphical representation of the cumulative results of experimental results and theoretical predictions.

OVERVIEW OF THE SELECTED REFERENCE CHARACTERS

(11) TABLE-US-00001 Pre-cast panel 110 Pre-cast panel width 112 Pre-cast panel distance from 114 pre-cast panel to structure Pre-cast panel to panel gap 116 Building floor 120 Perimeter Structural Beam 130 Bracket 140 Threaded Rod 150 Adjusting Nut 160 Bearing Connection 170 Crushing Tube 180 Coil Spring 200

DETAILED DESCRIPTION

(12) The representative embodiments are shown in FIGS. 1-6, where similar features share common reference numerals. The notation ′ ″ or characters A,B,C etc represent a repetition of the same element.

(13) Now referring to FIG. 1 which illustrates a side view of a multistory building 100 with architectural pre-cast panel 110 mounted on the side of the building, typically mounted one per building floor 120. The architectural pre-cast panel 110 is connected to the perimeter structural beam 130 using a bracket 140 via a threaded rod 150. The threaded rod 150 is securely affixed to the architectural pre-cast panel 110. At the base of the architectural pre-cast panel 110 is a bearing connection 170 that supports the weight of the architectural pre-cast panel 110. The architectural pre-cast panel 110 is positioned relative to the building floor 120 by adjusting nuts 160A/160B that are threaded onto the threaded rod 150. Placed on the threaded rod 150 are crushing tubes 180A/180B. The adjusting nut 160A/160B are tightened against the crushing tubes 180A/180B.

(14) Now referring to FIG. 2 which shows a close-up view of the crushing tubes 180A/180B which are placed on the threaded rod 150 on either side of the bracket 140. The crushing tubes 180A/180B are tightened against the bracket 140 via the adjusting nut 160A/160B on either side of the crushing tubes 180A/180B. The coil spring 200 is placed on the rod between the crushing tube and the adjusting nut.

(15) Now referring to FIG. 3 which shows an inward lateral movement 148 of the bracket 140 that is attached to the structural beam 130 relative to the pre-cast panel 110. The inward movement deforms 192B the crushing tube 180B and creates a deformed crushing tube 190B.

(16) Now referring to FIG. 1, FIG. 2 and FIG. 4A, whereby FIG. 4A shows an outward lateral movement 144 of the bracket 140 that is attached to the structural beam 130 relative to the precast panel 110. The outward movement compresses the coil spring 200 and creates a fully compressed spring 210.

(17) Now referring to FIG. 1, FIG. 2 and FIG. 4B, whereby FIG. 4B shows an additional outward lateral movement 145 of the bracket 142 that is attached to the structural beam 130 relative to the pre-cast panel 110. The additional outward movement deforms the crushing tube 180A and creates a deformed crushing tube 190A.

(18) Now referring to FIG. 5 which shows a close up view of the crushing tube 180A and a side view of the crushing tube 180B is as shown in FIG. 5A.

(19) Now referring to FIG. 6 which depicts a representative assembly having the threaded rod 150 that is approximately one inch in diameter with nuts that can thread on the rod. The crushing tube may have dimension of four or six or eight inches in height and two or three inches in width. It should appreciated by those of ordinary skill that the specific dimensional descriptions are exemplary only. Crushing tubes with other dimensions may be used that generally fall within the spirit and scope of the present inventive subject matter. The threaded rod 150 is typically connected to the architecture panel via an embedded u-shaped bar that has a welded plate to allow the passage of the threaded rod. Other means of securing the rod to the panel could be devised without changing the concept of the system.

(20) FIGS. 7, 8 and 9 are the graphical representation of the variation of yield load with respect to displacement for an 8 inches, 8.5 inches and 9.0 inches crushing tube respectively.

(21) Table-1 given below shows variation of yield with load for an 8 inch crushing tube. FIG. 7 describes the graphical representation 700 for the same. Thus for a 8 inches crushing tube the yield load increases with increasing displacement 710 and plateaus 720 at 10,750 pounds.

(22) TABLE-US-00002 TABLE 1 8 inches S.N Load PSI delta 1 500 100 0 2 1550 500 0 3 2850 1000 1/32 4 3550 1250 1/32 5 4175 1500 3/64 6 4850 1750 1/16 7 5500 2000 1/16 8 6800 2500 1/8  9 8175 3000 5/32 10 9450 3500 7/32 11 10750 4000 1/4  12 10750 4000 5/16 13 10750 4000 3/8  14 10750 4000 7/16 15 11400 4250 1/2  16 10750 4000 9/16 17 10750 4000 11/16  18 10750 4000 13/16  19 10750 4000 7/8  20 10750 4000 1 21 10750 4000 1 1/8    22 10750 4000 1 1/4   

(23) Table-2 given below shows variation of yield with load for an 8.5 inch crushing tube. FIG. 8 describes the graphical representation 800 for the same. Thus for a 8.5 inches crushing tube the yield load increases 810 with increasing displacement and plateaus 820 at 11,400 pounds.

(24) TABLE-US-00003 TABLE 2 8.5 inches S.N Load PSI delta 1 1550 500 0 2 2850 1000 0 3 4175 1500  1/32 4 4850 1750  1/16 5 5500 2000  1/16 6 6800 25000  3/32 7 8175 3000 1/8 8 9450 3500  3/16 9 10750 4000 1/4 10 11400 4250  5/16 11 11400 4250 3/8 12 11400 4250 1/2 13 11400 4250 5/8 14 11400 4100 3/4 15 11000 4000 15/16 16 10750 4000 1 1/16  17 10750 4000 1 3/16 

(25) Table-3 given below shows variation of yield with load for a 9.0 inch crushing tube. FIG. 9 describes the graphical representation 900 for the same. Thus for a 9.0 inch crushing tube the yield load increases with increasing displacement and plateaus 920 at 12,800 pounds.

(26) TABLE-US-00004 TABLE 3 9.0 inches S.N Load PSI delta 1 1550 500 0 2 2850 1000 0 3 4175 1500  1/32 4 4850 1750  1/16 5 4850 2000  1/16 6 6800 2500  3/32 7 8175 3000 1/8 8 9450 3500  3/16 9 10750 4000 1/4 10 12050 4500  5/16 11 12050 4500 3/8 12 13400 5000 1/2 13 14041 5250 5/8 14 13400 5000 3/4 15 13400 5000 15/16 16 12700 4750 1 1/16  17 12700 4750 1 3/16 

(27) The moment carrying capacity of a steel member M.sub.P also called as the plastic moment for the section of the tube wall can be calculated by the formula M.sub.P=Fy (Yield Stress)*z (Plastic section modulus); M.sub.P=57,290*b*0.188.sup.2/4; M.sub.P=506*b: Where b=Tube Length

(28) Further the yield load “P” on the whole tube can be calculated by the formula
P*0.62=4M.sub.P(1/2.625),thus P=2.46M.sub.P

(29) By assuming a 10% over strength factor, P=1245.3*1.1*b=1370*b

(30) For b (Tube Length)=4 inches: P=5480 Pounds

(31) For b (Tube Length)=12 inches: P=16440 Pounds

(32) FIG. 10 represents the graphical representation 1000 of the cumulative results based on the experimental findings and the theoretical predictions. Length of the tube (in inches) is plotted on the horizontal axis and the yield load (in pounds) is plotted on the vertical axis. 1010 and 1030 represent the two end points determined by theoretical calculations described above. The three central points 1020 are determined by experimental results described in FIGS. 7, 8 and 9. The linear equation for the line drawn through the experimental and theoretical results can be generally represented by y=1380.5x−83.796 with R.sup.2=0.9949. The conclusion drawn by these efforts is that the yield load is linearly proportional to tube length. This allows for designing the crushing tube to conform to the specific requirements of each application.

(33) Referring to Table-4 which represents the mill certificate showing the results for manufactured product—ASTM A500 GR B—2010, wherein “T” represents the thickness of the crushing tube as manufactured. All the material products were tested for variation in size, mechanical and chemical properties under various thermal conditions. A 0.188″ thickness crushing tube was used as the base sample for comparison purposes. The mill certificate certifies the products to be of the desired good quality and indicates the yield strength of the specific material used for the crushing tube.

(34) TABLE-US-00005 TABLE 4 Tensile Y.P S.N Heat No. T L (psi) (psi) 1. 472005537 0.188 40 65,702 46,977 2. 473005414 0.250 20 67,008 47,853 3. 473005419 0.250 40 65,267 46,290 4. 473002067 0.188 20 70,199 57,290 5. 473002067 0.188 40 70,199 57,290 6. 473005414 0.250 20 67,008 47,863

(35) Persons skilled in the art will recognize that many modifications and variations are possible in the details, materials, and arrangements of the parts and actions which have been described and illustrated in order to explain the nature of this inventive concept and that such modifications and variations do not depart from the spirit and scope of the teachings and claims contained therein.

(36) All patent and non-patent literature cited herein is hereby incorporated by references in its entirety for all purposes.