Metal Bolts Research Articles

1120 光ファイバセンサによるボルトの軸力計測法

A method for monitoring fastening force-by using a bolt embedded with an optical-fiber sensor (FBG)-has been developed. This method uses the shift of the optical fiber's wavelength that occurs when the metal bolt is subjected to a fastening force. In this study, it was first found that the strain measured by the FBG sensor depends on the adhesive strength of the interface between the optical fiber and the bolt. Secondly, it was found that the adhesive strength can be varied by changing the bore size. To measure the adhesive strength, loading tests were performed on several bolts. Lastly, by estimating a correction factor for the output of the FBG sensor, the actual strain in the bolt could be measured.

Excessively Long Metal Bolts Lead to Recall of Fluidotherapy Unit

Excessively Long Metal Bolts Lead to Recall of Fluidotherapy Unit

Comparison of Femoral and Tibial Pullout Forces in Bone–Patellar Tendon–Bone Anterior Cruciate Ligament Reconstructions With a New Interference Fixation Device

Summary: Interference screws have become the standard method for fixing bone–patellar tendon–bone (BPTB) grafts. To avoid the inherent pitfalls and complications of interference screws, a 28-mm long and from 5 to 7 mm spreadable metal bolt with nontapping threads was developed for this study. The technical applicability and biomechanical characteristics of this new BPTB interference fixation device were investigated by dissection or tensile testing of 48 cadaveric knee specimens from young donors. No problems occurred with respect to bone plug anchoring during insertion of the spreading bolts. The clinically important linear load was 920 ± 283 N for the femoral and 635 ± 247 N for the tibial fixation site. Bone plug pullout was the mode of failure in all specimens. The results of this study indicate that the spreading bolt is a reasonable alternative to interference screws.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 2 (March), 1999: pp 173–178

Joint characteristics of traditional Chinese wooden frames

The wooden frames of the remains of traditional Chinese architecture were built up using plug-slot type of beam-to-column connections without using any metal nails or bolts. One type of these connections commonly found in primary frames has been studied. Three different types of artificially degraded connections that imitate those deteriorated conditions naturally were investigated experimentally. The behaviour of these connections is found to be semirigid. They can be simulated by a three-parameter connection model. The effects of semirigid connections on frames were also studied through tests and the second-order elastic analysis by the Newton-Raphson method. It is shown that the behaviour of the frame is dominated by the characteristics of the connections. The proposed numerical method can accurately predict the response of the partially restrained wooden frame.

The Evidence of Aeneas Tacticus on the ΒΑΛΑΝΟΣ and ΒΑΛΑΝΑΓΡΑ

In preparing for the press an edition of Aeneas Tacticus, which was left in manuscript form by the late Mr. L. W. Hunter, I have had to consider a good deal the details of the fastening of the Greek city gate. The general principles are familiar to everyone: a gate with two wings (σανίδες) opening inwards only, with a wooden bar (μοχλός) placed horizontally across it on the inside, secured by a metal bolt (βάλανος) which passed through a vertical hole bored in the μοχλός and into a socket (βαλανοδόκη) in the stone beneath, the top of the βάλανος, when pushed home, being well below the top of the μοχλός. The βάλανος must have been a heavy iron pin, thick enough to stand a big strain, since if anyone tried to force the gate everything depended on the resistance of the βάλανος: I imagine it something like twelve inches long and two to three inches thick. It will be remembered that at Plataea in 431 B.C. a soldier fastened one of the gates στυρακίῳ ἀκοντίον ἀντι βαλάνου χρησάμενος ἐς τὸν μοχλόν (Thuc. ii. 4. 3).