Experimental and Analytical Investigation on the Nonlinear Behaviors of Glulam Moment-Resisting Joints Composed of Inclined Self-Tapping Screws with Steel Side Plates

Glulam moment-resisting joint composed of inclined self-tapping-screws (STS) with steel side plates were designed and its nonlinear moment-rotational skeleton curve was predicted by taking nonlinear load(P)-deformation(u) relationships of all moment-resisting components into considerations within step-wise linear calculation process. P-u relationships of all moment-resisting components were estimated by the fundamental shear joint tests or appropriate empirical relationships and they were approximated by the tetra polygonal-line curves or bi-linear curves. The extended Normalized Characteristic Loop (NCL) model, which was originally developed for RC construction, was applied to describe the hysteresis loops. For predicting failure load, the design equations for a mechanical joint loaded with inclination to the grain direction were applied. Three replications of T-shaped beam-column joint specimens were fabricated using Canadian spruce glulam beam and column. Connections of steel plates to glulam members were all composed of full-threaded inclined-STS. Static push-pull cyclic loading tests were conducted and observed behaviors were compared with step-wise linear calculation results. Agreements between predicted nonlinear behaviors and observed ones were good on the whole

Research of the size effect on shear strength of metal-plate connector joints in China

According to the reliability theory, the size effect has a great impact on the design value on shear strength of metal-plate connector. But little research has been done. So, based on GB/T50329-2002 of China, firstly, determining the size of metal-plate at different conditions, size effect tests were then conducted on metal-plate connectors composed of a type of Chinese metal-plate and 2# SPF dimension lumber from North America. A total of 125 metal-plate connectors are tested at five angles (90°, 60°T, 120°C, 150°C, 30°T), with Five kinds of widths (50mm，85mm，125mm，150mm，180mm) for each angle. Based on the testing data, fitting curve of size effect is presented, and width-effect parameters are estimated with SPSS(Statistic Package for Social Science). Results indicate that the width effect is significant; shear strength increases with the increase of width, and stays stable after a certain width

Analysis of Revenue Distribution of Assembly Building under EPC Model Based on Entropy Weight-TOPSIS Improved Shapley Value

Prefabricated construction has rapidly developed due to its efficiency and environmental benefits. With the widespread application of the EPC (Engineering, Procurement, and Construction) model, achieving fair and reasonable distribution of profits in prefabricated construction projects under this model has become an urgent issue that needs to be addressed. In response to the limitations of the traditional Shapley value method, this paper introduces input factors, technological factors, and management factors to develop an improved profit distribution model based on entropy-weighted TOPSIS and the Shapley value. A case study is presented to validate the model, aiming to achieve fair and equitable profit distribution

Analysis of Revenue Distribution of Assembly Building under EPC Model Based on Entropy Weight-TOPSIS Improved Shapley Value

Prefabricated construction has rapidly developed due to its efficiency and environmental benefits. With the widespread application of the EPC (Engineering, Procurement, and Construction) model, achieving fair and reasonable distribution of profits in prefabricated construction projects under this model has become an urgent issue that needs to be addressed. In response to the limitations of the traditional Shapley value method, this paper introduces input factors, technological factors, and management factors to develop an improved profit distribution model based on entropy-weighted TOPSIS and the Shapley value. A case study is presented to validate the model, aiming to achieve fair and equitable profit distribution

Research of the size effect on shear strength of metal-plate connector joints in China

According to the reliability theory, the size effect has a great impact on the design value on shear strength of metal-plate connector. But little research has been done. So, based on GB/T50329-2002 of China, firstly, determining the size of metal-plate at different conditions, size effect tests were then conducted on metal-plate connectors composed of a type of Chinese metal-plate and 2# SPF dimension lumber from North America. A total of 125 metal-plate connectors are tested at five angles (90°, 60°T, 120°C, 150°C, 30°T), with Five kinds of widths (50mm，85mm，125mm，150mm，180mm) for each angle. Based on the testing data, fitting curve of size effect is presented, and width-effect parameters are estimated with SPSS(Statistic Package for Social Science). Results indicate that the width effect is significant; shear strength increases with the increase of width, and stays stable after a certain width.</jats:p

Research of the size effect on shear strength of metal-plate connector joints in China

According to the reliability theory, the size effect has a great impact on the design value on shear strength of metal-plate connector. But little research has been done. So, based on GB/T50329-2002 of China, firstly, determining the size of metal-plate at different conditions, size effect tests were then conducted on metal-plate connectors composed of a type of Chinese metal-plate and 2# SPF dimension lumber from North America. A total of 125 metal-plate connectors are tested at five angles (90°, 60°T, 120°C, 150°C, 30°T), with Five kinds of widths (50mm，85mm，125mm，150mm，180mm) for each angle. Based on the testing data, fitting curve of size effect is presented, and width-effect parameters are estimated with SPSS(Statistic Package for Social Science). Results indicate that the width effect is significant; shear strength increases with the increase of width, and stays stable after a certain width

Effect of inclined self-tapping screws connecting laminated veneer lumber on the shear resistance

The load-bearing capacity and bearing stiffness formula of pin connectors in the current standard Eurocode 5 does not consider the influence of the angle on the single shear connection, especially for inclined screws connecting laminated veneer lumber (LVL). Therefore, research was conducted into the influence of the angle and friction on the load-bearing capacity and bearing stiffness of self-tapping screws connecting LVL made from Douglas fir. This study analyzed the existing calculation model of bearing capacity and stiffness and then derived a model with friction. The results showed that the load-bearing capacity and bearing stiffness in the tensile-shear mode was better than in the compression-shear mode, and that it was better with a 45° to 60° self-tapping screw angle. The lateral support can remarkably improve the bearing capacity and bearing stiffness in the compression-shear mode. The theoretical calculation formula for self-tapping screws connecting solid wood can better reflect the bearing capacity of inclined screws connecting LVL in the tensile-shear stress mode after increasing the fitting coefficient to 1.25. The safety factor was approximately 0.97 to 1.19. The proposed models in this paper are suitable for situations with friction in the compression-shear mode.</jats:p

Experimental and analytical investigation on the nonlinear behaviors of glulam moment-resisting joints composed of inclined self-tapping screws with steel side plates

Glulam moment-resisting joint composed of inclined self-tapping screws with steel side plates were designed and its nonlinear moment-rotational skeleton curve was predicted by taking nonlinear load ( P)–deformation ( u) relationships of all moment-resisting components into considerations within step-wise linear calculation process. P-u relationships of all moment-resisting components were estimated by the fundamental shear joint tests or appropriate empirical relationships, and they were approximated by the tetra polygonal line curves or bi-linear curves. The extended Normalized Characteristic Loop model, which was originally developed for reinforced concrete construction, was applied to describe the hysteresis loops. For predicting failure load, the design equations for a mechanical joint loaded with inclination to the grain direction were applied. Three replications of T-shaped beam-column joint specimens were fabricated using Canadian spruce glulam beam and column. Connections of steel plates to glulam members were all composed of full-threaded inclined self-tapping screws. Static push-pull cyclic loading tests were conducted and observed behaviors were compared with step-wise linear analytical results. Agreements between predicted nonlinear behaviors and observed ones were good on the whole. </jats:p

EFFECT OF EDGE DISTANCES ON STIFFNESS OF SHEAR-TENSION MODE IN GLULAM CONNECTIONS WITH INCLINED SCREWS

The effects of edge distances on stiffness in glulam connections with inclined self-tapping screws were studied in this paper. Under four anchorage angles (A-45°, A-60°, A-75°, A-90°) and three edge distances (EG-2D, EG-4D, EG-6D) conditions, the shear-tension tests were carried out on the timber structure connections with inclined self-tapping screws, and the stiffness and other properties of the connections were tested. Based on the results, the effects of edge distances on stiffness in joints were quantified using the equivalent energy elastic-plastic (EEEP) model. The results showed that the edge distances had a certain impact on the yield mode and load-carrying performance of the joints. Within a certain range of variation, as the edge distance increased, the stiffness of the connections increased gradually, showing a positive correlation. The stiffness of specimen EG-2D is 4.41 kN·mm-1. The stiffness of specimen EG-4D is 10.04 kN·mm-1, which increasesby 128% compared with the specimen EG-2D. The stiffness of specimen EG-6D is 12.08 kN·mm-1, which increases by 174% compared with the specimen EG-2D. However, the ductility coefficient, yielding load, and energy dissipatinghave no significant change. Within a reasonable edge distance, only ductile damage occurred.</jats:p