State-of-the-art of seismic response evaluation methods for metal roof spatial structures

[EN] The present paper is a result of a collaboration in IASS WG 8 for metal spatial structures to prepare state-ofthe-art reviews for earthquake response analysis methods and equivalent static seismic loads for metal spatial structures. It quotes mainly investigations from IASS symposia and related journals. First, the dynamic response characteristics of metal spatial structures are briefly explained. This is followed by a review of analytical methods for evaluating earthquake responses. Finally the equivalent seismic loads proposed for metal spatial structures are reviewed and some comments for future analysis of failure and fragility are provided.Nakazawa, S.; Kato, S.; Takeuchi, T.; Xue, S.; Lazaro, C. (2012). State-of-the-art of seismic response evaluation methods for metal roof spatial structures. Journal- International Association for Shell and Spatial Structures. 53(2):117-130. http://hdl.handle.net/10251/48932S11713053

Scaled dynamic loading tests on seismic isolation bearing excluding the contamination of friction and inertia forces

Conventional seismic isolation-bearing testing facilities require moving horizontal platens under high compression. However, these dynamic moving platens inevitably lead to the friction and inertial forces generated by large vertical loads and inertial forces due to the dynamic mass action of the moving platen, which eventually affects the accuracy of the measured force. To solve this problem, the authors have proposed a direct reaction force measurement system (horizontal-vertical separated type) that can exclude the contamination of friction and inertial forces. Measuring pure reaction forces without the contamination of friction forces and inertia is crucial for the reliability of test results. In this paper, prior to the construction of large-scale facility, reduced-size–mockup dynamic tests were conducted using the proposed measurement concept, and its validity and accuracy were discussed. Furthermore, this system was applied to hybrid simulation tests, and the significant improvement of the proposed measurement system was observed

State-of-Arts Views on Response Control Technologies on Metal Space Structures

p. 277-288Recently various kinds of passive response control techniques are taken into practice for buildings in seismic areas, and they start affecting on the architectural design itself. These trend affects also on spatial structures, and application of such techniques to domes, truss structures, or tension structures are recently increasing. Folllowing previous descussions [1], this paper firstly present the recent varieties of architectural expressions using seismic response controll technologies in buildings. Then, several important progresses in the application of passive control technology for metal spatial structures are introduced by refering recently realized projects, followed by discussions on their response characteristics and easy response evaluation methods.Takeuchi, T.; Ogawa, T.; Kumagai, T. (2009). State-of-Arts Views on Response Control Technologies on Metal Space Structures. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/650

Baseline tumour necrosis factor alpha levels predict the necessity for dose escalation of infliximab therapy in patients with rheumatoid arthritis

Objectives: To investigate the possible role of baseline plasma tumour necrosis factor alpha levels (baseline-TNF) on the clinical response to infliximab in patients with rheumatoid arthritis (RA). Methods: Patients with RA refractory to methotrexate received 3, 6, or 10 mg/kg of infliximab every 8 weeks, in a randomised, double-blind manner: the RISING study. Clinical response (disease activity score in 28 joints based on C-reactive protein or American College of Rheumatology core set) at week 54 and serum infliximab levels were compared in three patient groups with low, intermediate, or high baseline-TNF (TNF-low, TNF-int, or TNF-high). Results: In TNF-low patients, the clinical response to different doses of infliximab was comparable, whereas TNF-int patients exhibited a dose-dependent trend. In contrast, TNF-high patients (approximately 13% of the total patients) had a clinical response to 10 mg/kg significantly better than the response to 3 and 6 mg/kg of infliximab. In TNF-high patients, the median trough serum levels of infliximab were below the detection limit (<0.1 μg/ml) at 3 and 6 mg/kg but were greater than 2 μg/ml at 10 mg/kg, whereas the levels were approximately 1 μg/ml for each dosage group in TNF-low patients. Conclusion: In patients with RA, baseline-TNF is significantly associated with the clinical response to infliximab in patients with a high baseline-TNF. A higher dose of infliximab may be necessary in these patients, whereas lower doses of infliximab are sufficient for those with a low baseline-TNF. Baseline-TNF may be a useful measure for personalising the treatment of RA using infliximab