Two Pinned Arch Apparatus

The Two Pinned Arch Apparatus is a structural engineering laboratory system developed for experimental investigation of the behaviour of a two-pinned or two-hinged arch under different loading conditions.

A two-pinned arch is supported by hinges at its two ends. Unlike a three-pinned arch, it does not have an additional hinge at the crown. As a result, the idealized two-pinned arch is statically indeterminate to the first degree.

The apparatus enables students to investigate the horizontal reaction produced by a varying single point load on the arch.

Different load magnitudes can be applied at selected positions, and the experimentally obtained horizontal reaction can be compared with theoretically calculated values.

Students can also investigate the effect of a moving single point load. By changing the load position along the arch, the variation in horizontal reaction can be observed and analyzed.

This experiment provides a practical basis for studying influence lines and understanding how structural response at a particular location varies as a load moves across the structure.

The apparatus also supports experiments with a uniformly distributed load (UDL). Horizontal reactions produced by distributed loading can be determined and compared with theoretical structural-analysis results.

Another important topic is the principle of superposition. Under appropriate linear-elastic conditions, the structural effects produced by individual loads can be compared with their combined effect.

The system enables investigation of the line of thrust in an arch. This helps students understand how compressive forces are transmitted through the curved structural member under different loading arrangements.

Students can also perform the graphical construction of bending moment diagrams for point loads, providing a clear representation of moment variation along the arch.

The apparatus supports investigation of the secant assumption, an analytical approximation associated with arch behaviour and bending analysis.

Another important experiment is the determination of the maximum bending moment caused by an applied load on the arch.

The system therefore provides practical understanding of horizontal thrust, structural indeterminacy, influence lines, lines of thrust, bending moments, moving loads, distributed loads and arch behaviour.

Micro Technologies supplies Two Pinned Arch Apparatus and other Arch & Bridge Testing Equipment for engineering colleges, universities, polytechnic institutes and technical training centres.

Features

• Two-pinned / two-hinged arch configuration
• Statically indeterminate arch experiment
• Variable single point load studies
• Moving point load experiments
• Uniformly distributed load experiments
• Horizontal reaction determination
• Horizontal thrust investigation
• Influence line studies
• Principle of superposition experiments
• Line of thrust investigation
• Secant assumption study
• Bending moment analysis
• Graphical bending moment diagram construction
• Maximum bending moment investigation
• Experimental and theoretical comparison
• Robust educational laboratory construction

Benefits

• Provides practical understanding of two-pinned arches
• Demonstrates statically indeterminate structural behaviour
• Enables horizontal reaction determination
• Shows the influence of point-load magnitude
• Demonstrates the effect of moving load position
• Supports uniformly distributed loading experiments
• Helps students understand influence lines
• Provides practical investigation of thrust lines
• Supports secant assumption studies
• Enables bending moment diagram construction
• Helps determine maximum bending moments
• Connects theoretical arch analysis with experiments

Product Specifications

Experiments Performed

• Study of a two-pinned arch
• Determination of horizontal reaction due to a varying single point load
• Comparison of measured horizontal reaction with theoretical values
• Determination of horizontal reaction due to a moving point load
• Study of horizontal reaction versus load position
• Determination of horizontal reaction due to uniformly distributed loading
• Investigation of structural indeterminacy
• Construction of influence lines
• Verification of the principle of superposition
• Investigation of lines of thrust in an arch
• Study of horizontal thrust
• Graphical construction of bending moment diagrams
• Bending moment analysis for point loads
• Investigation of the secant assumption
• Determination of maximum bending moment due to an applied load
• Comparison of theoretical and experimental results

Applications

• Arch & Bridge Testing Laboratories
• Structural Engineering Laboratories
• Structural Mechanics Laboratories
• Structural Analysis Laboratories
• Civil Engineering Laboratories
• Mechanics of Structures Laboratories
• Strength of Materials Laboratories
• Engineering Mechanics Laboratories
• Applied Mechanics Laboratories
• Engineering Colleges
• Universities
• Polytechnic Institutes
• Technical Training Centres
• Educational & Research Laboratories

FAQs

What is the Two Pinned Arch Apparatus used for?

The apparatus is used to investigate horizontal reactions, thrust lines, influence lines and bending moments in a two-pinned arch under different loading conditions.

What is a two-pinned arch?

A two-pinned or two-hinged arch has hinged supports at both ends but no crown hinge, making the idealized structure statically indeterminate.

Is a two-pinned arch statically determinate?

No. A conventional planar two-pinned arch is generally statically indeterminate to the first degree.

Can horizontal reaction be determined experimentally?

Yes. Horizontal reactions can be investigated for different point-load, moving-load and distributed-load conditions.

Can a moving point load be studied?

Yes. A point load can be moved to different positions along the arch to investigate changes in horizontal reaction and structural response.

Can uniformly distributed loading be investigated?

Yes. The apparatus supports UDL experiments for studying horizontal reactions in the arch.

Can influence lines be studied?

Yes. Moving-load measurements can be used to construct and analyze influence lines for selected structural responses.

Can the line of thrust be investigated?

Yes. The apparatus enables practical study of the line of thrust and its relationship with arch geometry and loading.

Can bending moment diagrams be constructed?

Yes. Bending moment diagrams for point-loading conditions can be developed graphically and compared with analytical results.

What is the secant assumption used for?

The secant assumption is an analytical approximation that can be used in the study of arch geometry and structural response, depending on the adopted arch-analysis method.

Can maximum bending moment be determined?

Yes. Students can investigate the magnitude and location of maximum bending moment produced by applied loading.

What is the difference between two-pinned and three-pinned arches?

A three-pinned arch has an additional crown hinge and is statically determinate, while a two-pinned arch lacks the crown hinge and is generally statically indeterminate to the first degree.

Why Choose Our Products

• Two-pinned arch experiments
• Point, moving and UDL loading studies
• Horizontal reaction determination
• Structural indeterminacy demonstration
• Influence line experiments
• Line of thrust investigation
• Secant assumption studies
• Bending moment analysis
• Maximum bending moment investigation
• Experimental and theoretical comparison
• Customized configurations available
• Institutional and bulk supply support

Call to Action

Expand your Arch & Bridge Testing Laboratory with the Two Pinned Arch Apparatus from Micro Technologies. Designed for practical investigation of horizontal thrust, influence lines, bending moments and statically indeterminate arch behaviour, the system is suitable for universities, engineering colleges and technical institutes. Contact us for technical specifications, customized configurations, institutional quotations, bulk orders or tender supply.