Shear wall aspect ratio reducing frame (ARRF)

Abstract

My invention, the Shear Wall Aspect Ratio Reducing Frame is a simple, economical, efficient, easy to install device that allows greater oppotunity and flexibility in the size and location of openings in the walls of wood frame constructed buildings particularly houses. The ARRF would replace the commercial, pre-fabricated systems now in use which are costly and inefficient labor-intensive shear wall devices. The ARRF achieves its goal by reducing the moment arm in the overturning equations that are used to determine the uplift forces in a shear wall. The ARRF reduces forces in walls rather than increase their bulk which is the strategic concept now in use throughout the design professions and the construction industry to solve the aspect ratio problem.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001]“Not Applicable”STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT [0002]“Not Applicable”REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX [0003]“Not Applicable”BACKGROUND OF THE INVENTION [0004] This invention pertains to the field of residential wood frame construction. There is a challenge in wood frame construction to resist loads on structures generated by lateral forces, i.e. wind and earthquakes. Most region of the United States are confronted by one or the other and in most areas—both. [0005] Lateral forces are typically resisted by shear walls in economical wood frame construction or, when the aspect ratio of two to one is exceeded Two being the heighth and one being the width, by pre-fabricated heavy duty “strong walls”. Due to the expense and complexity of strong wall assemblies, residential house designers try to avoid using walls that have an excessive aspect ratio. The...

AI Technical Summary

Benefits of technology

[0008] This invention, the ARRF, reduces forces on a shear wall by 50% making it unnecessary to provide a full heighth, heavy duty, pre-fabricated strong wall shear walls in narrow shear resisting sections of wall. The aforementioned manufacturers of high-strength walls provide greater shear force resisting capacity than that provided by conventional wood frame construction by means of heftier components without regard to the aspect ratio of the wall. These products increase shear capacity (pounds per foot of resistance) and uplift force resistance capacity (pounds of force) by bulk increases in the size and strength of their respective assemblies as well as from stronger connections of those pieces to each other and to the adjacent reinforced concrete foundation (lower connection) and the top plate (upper connection).

[0009] This invention, the ARRF, reduces the aspect ratio of a narrow wall to a size that is greater than the code mandated minimum (2:1) thus allowing standard construction between the ARRF and the top plate. The ARRF reduces the uplift forces that are generated by lateral force induced overturning moments in the wood frame wall components by half i.e a 10,000 pound uplift force is reduced to a 5,000 pound uplift force.

[0010] The ARRF is only one-half as high as the wall in which it is placed which makes it easy to install. The ARRF does not have to fit into a precise zone as defined by the top surface of the concrete stem wall and the underside of the top plate as is the case for all other pre-fabricated strong walls. The ARRF is easy to install using semi-skilled workers.

Problems solved by technology

There is a challenge in wood frame construction to resist loads on structures generated by lateral forces, i.e. wind and earthquakes.

Due to the expense and complexity of strong wall assemblies, residential house designers try to avoid using walls that have an excessive aspect ratio.

A specific existing problem with the three most prominent commercially available pre-fabricated strong walls: Simpson Strong Wall, Hardy Frame and Truss-Joist Shear Panel is that they are costly and they require a highly skilled carpenter and considerable site preparation for their installation.

They are tall and heavy and the smallest of them require two men to lift and to install.

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