Collapsing process simulations of timber structures under dynamic loading II: simplification and quantification of the calculating method
In a previous paper we presented the efficacy of the extended distinct element method (EDEM) on the collapsing process simulation of timber-frame structures. The results obtained were qualitative, and the need for quantitative simulation was pointed out. In this report, we improved our simulating programs with the aim of establishing a quantitative simulation by EDEM. For this purpose, the parameters of the frame members (beam or column) were determined by comparing the simulated results of four-point bending tests with experimental results. Other parameters of plywood and joint members were determined by simulations of two rail shear and slip tests of joint parts, respectively. Using these parameters we made simulations of the collapsing process of an actual-size plywood-sheathed wall and at the same time carried out the experiments under similar conditions. Simulated load–displacement curves of the plywood-sheathed wall were similar to those obtained in the experiments, and the sequence of failure at nailed joints of the simulation model gave good agreement with that of the experimental collapsing processes. Using these processes, we believe that we established a basic quantitative simulation method to test the collapsing process of timber-frame structures.
COLLAPSE SIMULATION OF AMMU HAWU TRADITIONAL TIMBER HOUSE
Most parts of Indonesia are quite exposed to the risk of major
earthquakes, but many traditional timber houses were survived due to
earthquake. One of Indonesian traditional timber house is Omo Hada, an
indigenous house of Nias people was survived with no damage after the Mw 8.6
Northern Sumatra Earthquake. In Japan, many residential building has been built
by using wood material in order to prevent collapse during major earthquake.
Wood is considered as one of the most important and reliable construction
materials, since it is a renewable and has low weight due to its properties.
Collapse mechanism of Ammu Hawu Traditional House with Palm wood
(Borassus flabellifer) as main material was analyzed by using Wallstat software
and Extended Distinct Element Method (EDEM) as the basis theory. Wallstat is a
collapse analysis program which already used in many previous researches to
simulate collapse during times of seismic motion. In this study, there are ten
models that were analyzed due to El Centro Earthquake 1940, Kobe Earthquake
1995 and Modified El Centro Earthquake 1940, those are, Model 0, 1, 2, 3, 4, 5
up to 11. Model 0 is original model with no reinforcement. In the Model 1, 2, 3,
4, and 5 are the models reinforced with additional vertical shear wall at second
story. Model 6, 7, 8, and 9 are the models reinforced with bracing at the first
story columns. Whereas in Model 10 is Model 5 which are subjected to modified
El Centro Earthquake 1940.
The models reinforced with vertical shear walls at second story collapsed and
it was found that soft-story occurred due to the El Centro and Kobe Earthquake.
It was also found that base shear force values in Model 3 through 5 are higher
than the original model, that is, Model 0. Otherwise, Model 6 through 9 survived
and the base shear force are smaller than that of Model 0. This bracing
reinforcement system showed the effectiveness in preventing earthquake and
base shear force to whole structure. Soft-story did not occur in these models.
Model 10 also survived due to modified El Centro earthquake. It indicates that
the still survive due to local scale earthquake. Moreover, internal force values in
all models are higher than the original model. From all those aforementioned
parameters, it can be concluded that bracing reinforcement at first story is more
effective in preventing structure from collapsing due to earthquake than the
models with additional vertical shear walls at second story.
Keywords: Ammu Hawu traditional house, Borassus flabellifer, Wallstat
software, Extended Distinct Element Method (EDEM), Vertical shear wall,
Brace, Collapse mechanism.
The Meaning of Wisdom in James: Examination of a Hypothesis
The following essay is an attempt to examine the manner in which the writer of the Epistle of James uses the concept of Wisdom; and to study the suggestion that the way in which he uses it is more or less interchangeable with that in which other writers of the New Testament use the concept of the Holy Spirit.