Nhri-4000 High Performance Contact Surface Direct Shear Apparatus

With the rapid development of China's national economy, Lots of high buildings, high altitude of the dam, the Gulf projects, port construction, water conservancy projects construction and remediation projects. Researchers who is engaged in soil mechanics required relating to static dynamics study of the soil with different material structure contact surface. These issues relate to non-linear, large deformation, the local discontinuous mechanical forefront of questions etc.. It is one of the research cores of soil structure interaction studies. The basic approach of the contact surface mechanics property research is through the contact surface of the basic mechanics property test, research main factors and basic law of the contact surface mechanics property affected, and establish describing the constitutive relationship of contact surface mechanics property.The main significance of developing NHRI-4000 High Performance Large Contact Surface Shear Test Apparatus is through this equipment to research friction property of the different materials, utilize this equipment to carry out the contact surface load test between rough particle soil and the structure material to research the deformation mechanism and the regularity in loading. Through this apparatus, under the different normal force, to test the resisting shear strength between the soil and the structure material in order to study the friction characteristics between the soil and the different structure materials.The apparatus consists of the executing device, test device and control software. Through the computer to control two executing devices to realize compression characteristics of the soil and structure material under the stress control and the strain control and also to realize iso-shear surface of direct shear test and varying shear surface of direct shear test. As a result of adopting computer software for different test requirements of flexible control and the data automatic test techniques, it greatly facilitate the researchers on soil testing so that they can from both macro and micro aspects to carry out accurate test of the contact surface deformation. The apparatus developed for the soil test is to provide large pressure range and flexible control and satisfied scientific research need in the field of geotechnical construction.The control precision of normal force and shear force is studied.Use the test data of normal force and shear force, combine computer algorithms, closed-loop control servo motor speed so as to achieve control precision requirements of normal force and shear force.The control mode is researched. Use epistatic PC and under-bit PC data exchange to realize that the espistatic PC controls under-bit PC.The stability of the test data has studied. At the hardware circuitry, use low-pass filter of the circuit etc. technologies to ensure the stability of the signal; In software, use a simple moving average technique, from software, to solve the external environment interference to the data.The communications data reliability has studied. To adopt odd even parity and eigenvalue inspection to ensure the data accuracy.Delphi programming language has studied, use data bank to data storage, real-time chart display.