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9This paper describes an experimental test program and theoretical analysis which examines the reinforcing in flexure 10 of glued laminated timber (glulam) beams using bonded-in carbon fiber reinforced polymer (CFRP) bars. A series of 11 four-point bending tests were conducted till failure on unreinforced, passively reinforced and prestressed Douglas fir 12 glulam beams in a simply-supported scheme. The focus of this research was to evaluate the reinforcing efficiency of 13 both passively reinforced and prestressed beams. Test results showed that the flexural capacity of the reinforced, 14 prestressed, prestressed & reinforced (bottom prestressed and top reinforced) beams greatly increased by 64.8%, 15 93.3% and 131%, respectively. While the maximum improvement of the bending stiffness reached 42.0%. Another 16 important finding was that the extreme fiber tensile strain of timber beams at failure could be remarkably increased 17 due to the presence of the tension reinforcement, which indicated it overcomes the effects of local defects and 18 therefore the failure mode was changed from brittle tension failure to ductile compression failure. Based on the 19 experimental results, a theoretical model was proposed to predict the flexural capacity of unreinforced, reinforced 20 and prestressed timber beams, which was validated by the test data. 21 2 in Europe and is widely used nowadays in buildings and bridges [1]. Glulam has an excellent strength-to-weight ratio, 27shape and size flexibility, as well as high strength and dimensional stability. 28However, despite all of these benefits, glulam beams are usually underused due to the naturally defects such as knots 29 and cross grain [2]. Another problem is the relative low stiffness as a result of which the design of glulam beams is 30 often controlled by deflection limits [3]. For these reasons, many attempts have been made to reinforce or strengthen 31 glulam or solid timber beams by using high tensile strength materials. In the earlier decades, the majority of this 32 work focused on the use of metallic reinforcement [4][5][6][7]. More recently fiber reinforced polymers (FRP) was used as 33 structural reinforcement for timber beams, which in the form of sheets, plates and bars [8][9][10][11][12][13][14][15][16][17][18][19]. It showed from these 34 researches that the reinforcement in the tension zone would improve the strength, stiffness and ductility. Furthermore, 35 both short-term and long-term deflections of the reinforced timber beams were decreased [3,20]. 36But the reinforcing materials usually has a notable higher ultimate tensile strain than that of wood, which means it 37was not effectively used while the failure occurs in this kind of timber members with passive reinforcement. Thus its 38 economic efficiency was argued by some researchers [21,22]. Attempt then was made by introducing prestress in 39 reinforcing materials [2,[23][24][25][26][27]. As a result, the flexural strength is further increased due to the full use of both FRP 40 and wood, while bendi...

This paper presents an analytical method of the determination of the moment resistance, initial stiffness and the rotation capacity of glulam beam-column connections with glued-in rods. The methodology is based on the component method and is implemented using appropriate mechanical models. As a simplified component of the steel box sections, the substitute T-stub in the model is well verified by the experimental results, whether with or without the transverse web stiffeners. On the basis of the mechanical properties of the individual components such as initial stiffness, load resistance and a further force-deformation relationship, the moment-rotation curves of the entire joint can be obtained. The proposed model is evaluated against the experimental results, which shows good agreement between the two.

Background Elastography is a promising way to evaluate tissue differences regarding stiffness, and the stiffness of the malignant breast lesions increased at the lesion margin. However, there is a lack of data on the value of the shear wave elastography (SWE) parameters of the surrounding tissue (shell) of different diameter on the diagnosis of benign and malignant breast lesions. Therefore, the purpose of our study was to evaluate the diagnostic performance of shell elasticity in the diagnosis of benign and malignant breast lesions using SWE. Methods Between September 2016 and June 2017, women with breast lesions underwent both conventional ultrasound (US) and SWE. Elastic values of the lesions peripheral tissue were determined according to the shell size, which was automatically drawn along the edge of the lesion using the following software guidelines: (1): 1 mm; (2): 2 mm; and (3): 3 mm. Quantitative elastographic features of the inner lesions and shell, including the elasticity mean (Emean), elasticity maximum (Emax), and elasticity minimum (Emin), were calculated using an online-available software. The receiver operating characteristic curves (ROCs) of the elastographic features was analyzed to assess the diagnostic performance, and the area under curve (AUC) of each elastographic feature was obtained. Logistic regression analysis was used to predict significant factors of malignancy, permitting the design of predictive models. Results This prospective study included 63 breast lesions of 63 women. Of the 63 lesions, 33 were malignant and 30 were benign. The diagnostic performance of Emax-3shell was the highest (AUC = 0.76) with a sensitivity of 60.6% and a specificity of 83.3%. According to stepwise logistic regression analysis, the Emax-3shell and the Emin-3shell were significant predictors of malignancy (p < 0.05). The AUC of the predictive equation was 0.86. Conclusions SWE features, particularly the combination of Emax-3shell and Emin-3shell can improve the diagnosis of breast lesions.

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