Self-tapping Screws as Reinforcement Perpendicular to the Grain in Timber Connections
نویسندگان
چکیده
The use of self-tapping screws with continuous threads as a reinforcement to avoid splitting of members in connections with dowel-type fasteners was studied in two projects carried out at the Universities of Nottingham and Karlsruhe. The reinforced specimens showed a very ductile failure mode whereas the non-reinforced specimens failed in a brittle way. Although the reinforced specimens also showed small cracks in the wood directly under the dowels, a complete splitting of the whole specimen, as regularly observed in the tests with the non-reinforced connections, did not occur. A model for calculating the load in the reinforcing screws was developed and its use is shown in some examples.
منابع مشابه
Bolted Timber Joints with Self-tapping Screws
The use of self-tapping screws with continuous threads in the joint area as a reinforcement to avoid splitting of timber members is studied. A theoretical model is developed to calculate the stress distribution around a pin-loaded hole in a timber joint, to predict brittle failure modes in bolted connections and to calculate the load in the reinforcing screws. Laboratory experiments on reinforc...
متن کاملTests to Determine the Joint Stiffness and Resisting Moment Capacity of Joints in Timber-Framed Houses
Wind and earthquake disasters in the world often cause billions of dollars of damage to buildings, most of which is to non-engineered buildings-especially homes. Wood-frame homes use connectors which exhibit partial rotational rigidity at the member ends, making analytical solutions difficult. This is due to the lack of information about the complex behavior of the connections used in this type...
متن کاملFinite Element Prediction of the Behavior of Profiled Steel Sheet Dry Board Folded Plate Structures an Improved Model (RESEARCH NOTE)
This paper describes an alternative finite element model that would yield more accurate results in the prediction of the behavior of Profiled Steel Sheet Dry Board (PSSDB) folded plate structures, which can be considered as an improvement of an earlier proposed model. The PSSDB folded plate structures are being proposed as an alternative to traditional forms of roof construction.The PSSDB syste...
متن کاملBiomechanical Evaluation of the Influence of Cervical Screws Tapping and Design
OBJECTIVE To assess if the screw design (self-drilling/self-tapping) and the pilot hole tapping could affect the insertion torque and screw pullout strength of the screw used in anterior fixation of the cervical spine. METHODS Forty self-tapping screws and 20 self-drilling screws were inserted into 10 models of artificial bone and 10 cervical vertebrae of sheep. The studied parameters were th...
متن کاملAutomated surgical screwdriver: automated screw placement.
The use of power screwdrivers and drills for tapping and screw insertion in surgery is becoming more common. It has been established from clinical observations that the use of a small air drill for inserting self-tapping screws provides improved coaxial alignment and precision, and that the drill should be stopped before the screw head is completely seated on the plate, presumably to reduce the...
متن کامل