Atsushi Wada

Modification of the luminescence spectra of chloro(tetrapyridylcyclotetramine)europium complexes by fine tuning of the Eu–Cl distance with outer-sphere counterions in the solid state, in a polymer matrix and in solution

Controlling the coordination environments and the luminescence properties of Eu(3+) complexes with outer-sphere counterions was achieved in the solid state, in a polymer matrix and in solution.

A loop test to measure the strength of monofilaments used for advanced composites

This paper presents a methodology to measure the strength of monofilaments which are commonly used for fiber-reinforced composite materials. A so-called loop test is adopted for the present test. Because the loop test has some disadvantages in the measurement of the strength of monofilaments, we combined it with the elastica, by which combination the bending strength of monofilaments can be obtained. This method was successfully applied to a carbon fiber. During these tests it has been made clear that this method can be used to evaluate the strength of monofilaments. Some statistical discussion was also conducted.

Eccentric compression bending test for CFRP pipe

This paper reports a new test method to evaluate the bending strength of composite pipes. In the past, we proposed a compression bending test method to get more reliable bending strength values than the conventional three- or four-point bending test. This compression bending was successfully applied not only to flat CFRP coupons but also to slender CFRP pipes. However, if the diameter of the pipe is relatively large, this compression bending is not necessarily appropriate. Therefore, as a step forward to accurate determination of compression bending, an eccentric compression bending test method is tried in the present paper.

Development of Compression Bending Test Method for Advanced Composites - A Review

This paper reviews a series of our research works in developing a compression bending test method. This idea was invented to get rid of undesirable effect of loading devices in a conventional 3or 4-point bending test. Starting from the basic concept, some refinements of data reduction methodology and some advancements of test fixtures are described in conjunction with the application to flat coupons as well as pipe configurations. The most recent work of an eccentric compression bending test is also reviewed. INTRODUCTION region and this is the main benefit of the present method. Wisnom 15, 6/ applied the same idea to evaluate the compressive failure stress and/or strain of composites rather than bending strength. In the present paper, the essence of our works is presented step by step. The major subjects are (1) how to measure the bending strength 111, (2) how to measure the bending modulus /8, 9/, and (3) a simplification of the test device /10/. The above works were conducted using flat coupons whereas test results for pipe configuration / l l / are also reported in the present paper. Further, an eccentric compression bending test /12/, which is an advancement of the compression bending test, is briefly reviewed. It is well known that the bending strength of CFRP coupon is strongly affected by the stress concentration due to a stiff loading device in a 3or 4-point bending test. The works of Whitney /1 / and Cui and Wisnom 121 are some examples addressing this stress concentration effect. The work of Hojo, et al. 13/ focused on reducing the stress concentration by inserting a soft film between the test specimen and the loading devices and this idea was adopted in the J IS (Japanese Industrial Standard) as a recommendation /4/. To compensate for this undesirable effect of the stress concentration due to the loading device, we have developed an additional approach. That is, if an axial load is applied to a column, it will buckle (Euler buckling) and eventually the bar will break at the middle of the span. The present review focuses on the compression bending caused by Euler buckling. In this case, there is no loading device at around the failure HOW TO MEASURE THE BENDING STRENGTH As was mentioned in the Introduction, the present idea is based on the Euler buckling of a pin-ended column. Figure 1 shows the half length of the present specimen. The experimental methodology is based on the Euler buckling of the specimen. The bending moment at the midspan A is